Fix DB Syntax Error when there are multiple assignees

@monish whilst reviewing the ConfigAndLog files I came across this syntax error

Nov 19 09:33:58  [error] $Fatal Error Details = Array
(
    [callback] => Array
        (
            [0] => CRM_Core_Error
            [1] => exceptionHandler
        )

    [code] => -2
    [message] => DB Error: syntax error
    [mode] => 16
    [debug_info] => SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contact_id = 427306,590497 LIMIT 1 [nativecode=1064 ** You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '590497 LIMIT 1' at line 1]
    [type] => DB_Error
    [user_info] => SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contact_id = 427306,590497 LIMIT 1 [nativecode=1064 ** You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '590497 LIMIT 1' at line 1]
    [to_string] => [db_error: message="DB Error: syntax error" code=-2 mode=callback callback=CRM_Core_Error::exceptionHandler prefix="" info="SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contact_id = 427306,590497 LIMIT 1 [nativecode=1064 ** You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '590497 LIMIT 1' at line 1]"]
)


Nov 19 09:33:58  [debug] $backTrace = #0 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/Error.php(942): CRM_Core_Error::backtrace("backTrace", TRUE)
#1 /var/www/www.autismontario.com/vendor/pear/pear-core-minimal/src/PEAR.php(944): CRM_Core_Error::exceptionHandler(Object(DB_Error))
#2 /var/www/www.autismontario.com/vendor/pear/db/DB.php(997): PEAR_Error->__construct("DB Error: syntax error", -2, 16, (Array:2), "SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#3 /var/www/www.autismontario.com/vendor/pear/pear-core-minimal/src/PEAR.php(575): DB_Error->__construct(-2, 16, (Array:2), "SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#4 /var/www/www.autismontario.com/vendor/pear/pear-core-minimal/src/PEAR.php(223): PEAR->_raiseError(Object(DB_mysqli), NULL, -2, 16, (Array:2), "SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...", "DB_Error", TRUE)
#5 /var/www/www.autismontario.com/vendor/pear/db/DB/common.php(1928): PEAR->__call("raiseError", (Array:7))
#6 /var/www/www.autismontario.com/vendor/pear/db/DB/mysqli.php(936): DB_common->raiseError(-2, NULL, NULL, "SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...", "1064 ** You have an error in your SQL syntax; check the manual that correspon...")
#7 /var/www/www.autismontario.com/vendor/pear/db/DB/mysqli.php(406): DB_mysqli->mysqliRaiseError()
#8 /var/www/www.autismontario.com/vendor/pear/db/DB/common.php(1234): DB_mysqli->simpleQuery("SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#9 /var/www/www.autismontario.com/vendor/civicrm/civicrm-packages/DB/DataObject.php(2696): DB_common->query("SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#10 /var/www/www.autismontario.com/vendor/civicrm/civicrm-packages/DB/DataObject.php(1829): DB_DataObject->_query("SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#11 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/DAO.php(454): DB_DataObject->query("SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#12 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/DAO.php(1637): CRM_Core_DAO->query("SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...", TRUE)
#13 /var/www/www.autismontario.com/htdocs/sites/default/civicrm/ext/biz.jmaconsulting.ao/ao.php(114): CRM_Core_DAO::singleValueQuery("SELECT 1 FROM civicrm_email WHERE email LIKE '%@autismontario.com' AND contac...")
#14 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Utils/Hook.php(287): ao_civicrm_validateForm("CRM_Activity_Form_Activity", (Array:49), (Array:0), Object(CRM_Activity_Form_Activity), (Array:0))
#15 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Utils/Hook/DrupalBase.php(73): CRM_Utils_Hook->runHooks((Array:227), "civicrm_validateForm", 5, "CRM_Activity_Form_Activity", (Array:49), (Array:0), Object(CRM_Activity_Form_Activity), (Array:0), NULL)
#16 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/Civi/Core/CiviEventDispatcher.php(184): CRM_Utils_Hook_DrupalBase->invokeViaUF(5, "CRM_Activity_Form_Activity", (Array:49), (Array:0), Object(CRM_Activity_Form_Activity), (Array:0), NULL, "civicrm_validateForm")
#17 /var/www/www.autismontario.com/vendor/symfony/event-dispatcher/EventDispatcher.php(214): Civi\Core\CiviEventDispatcher::delegateToUF(Object(Civi\Core\Event\GenericHookEvent), "hook_civicrm_validateForm", Object(Civi\Core\CiviEventDispatcher))
#18 /var/www/www.autismontario.com/vendor/symfony/event-dispatcher/EventDispatcher.php(44): Symfony\Component\EventDispatcher\EventDispatcher->doDispatch((Array:1), "hook_civicrm_validateForm", Object(Civi\Core\Event\GenericHookEvent))
#19 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/Civi/Core/CiviEventDispatcher.php(129): Symfony\Component\EventDispatcher\EventDispatcher->dispatch("hook_civicrm_validateForm", Object(Civi\Core\Event\GenericHookEvent))
#20 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Utils/Hook.php(167): Civi\Core\CiviEventDispatcher->dispatch("hook_civicrm_validateForm", Object(Civi\Core\Event\GenericHookEvent))
#21 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Utils/Hook.php(512): CRM_Utils_Hook->invoke((Array:5), "CRM_Activity_Form_Activity", (Array:49), (Array:0), Object(CRM_Activity_Form_Activity), (Array:0), NULL, "civicrm_validateForm")
#22 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/Form.php(585): CRM_Utils_Hook::validateForm("CRM_Activity_Form_Activity", (Array:49), (Array:0), Object(CRM_Activity_Form_Activity), (Array:0))
#23 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/QuickForm/Action/Upload.php(136): CRM_Core_Form->validate()
#24 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/QuickForm/Action/Upload.php(119): CRM_Core_QuickForm_Action_Upload->realPerform(Object(CRM_Activity_Form_Activity), "upload")
#25 /var/www/www.autismontario.com/vendor/civicrm/civicrm-packages/HTML/QuickForm/Controller.php(203): CRM_Core_QuickForm_Action_Upload->perform(Object(CRM_Activity_Form_Activity), "upload")
#26 /var/www/www.autismontario.com/vendor/civicrm/civicrm-packages/HTML/QuickForm/Page.php(103): HTML_QuickForm_Controller->handle(Object(CRM_Activity_Form_Activity), "upload")
#27 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/Controller.php(347): HTML_QuickForm_Page->handle("upload")
#28 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Utils/Wrapper.php(98): CRM_Core_Controller->run()
#29 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/Invoke.php(285): CRM_Utils_Wrapper->run("CRM_Activity_Form_Activity", "Activities", (Array:1))
#30 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/Invoke.php(68): CRM_Core_Invoke::runItem((Array:14))
#31 /var/www/www.autismontario.com/vendor/civicrm/civicrm-core/CRM/Core/Invoke.php(36): CRM_Core_Invoke::_invoke((Array:3))
#32 /var/www/www.autismontario.com/htdocs/modules/contrib/civicrm/src/Civicrm.php(88): CRM_Core_Invoke::invoke((Array:3))
#33 /var/www/www.autismontario.com/htdocs/modules/contrib/civicrm/src/Controller/CivicrmController.php(80): Drupal\civicrm\Civicrm->invoke((Array:3))
#34 [internal function](): Drupal\civicrm\Controller\CivicrmController->main((Array:3), "")
#35 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array((Array:2), (Array:2))
#36 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/Render/Renderer.php(582): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#37 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#38 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext((Array:2), (Array:2))
#39 /var/www/www.autismontario.com/vendor/symfony/http-kernel/HttpKernel.php(151): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#40 /var/www/www.autismontario.com/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#41 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/StackMiddleware/Session.php(57): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#42 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(47): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#43 /var/www/www.autismontario.com/htdocs/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#44 /var/www/www.autismontario.com/htdocs/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#45 /var/www/www.autismontario.com/htdocs/core/modules/ban/src/BanMiddleware.php(50): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#46 /var/www/www.autismontario.com/htdocs/modules/contrib/shield/src/ShieldMiddleware.php(84): Drupal\ban\BanMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#47 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(47): Drupal\shield\ShieldMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#48 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(52): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#49 /var/www/www.autismontario.com/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#50 /var/www/www.autismontario.com/htdocs/core/lib/Drupal/Core/DrupalKernel.php(693): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, TRUE)
#51 /var/www/www.autismontario.com/htdocs/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#52 {main}

I believe this will fix the error can you check on staging if the check still works correctly