Fixed using field that is unavailable in some module

modules/Settings/Workflows/views/EditTask.php

@@ -136,9 +136,12 @@ class Settings_Workflows_EditTask_View extends Settings_Vtiger_Index_View {
 		}
         
         $usersModuleModel = Vtiger_Module_Model::getInstance('Users');
-        $emailFieldoptions .= '<option value=",$(general : (__VtigerMeta__) reports_to_id)"> '.
+
+		if ($moduleModel->getField('assigned_user_id')) {
+        	$emailFieldoptions .= '<option value=",$(general : (__VtigerMeta__) reports_to_id)"> '.
                                     vtranslate($moduleModel->getField('assigned_user_id')->get('label'),'Users').' : (' . vtranslate('Users','Users') . ') '. vtranslate($usersModuleModel->getField('reports_to_id')->get('label'),'Users') .'</option>';
-        
+		}
+		
 		$nameFields = $recordStructureInstance->getNameFields();
 		$fromEmailFieldOptions = '<option value="">'. vtranslate('Optional', $qualifiedModuleName) .'</option>';
 		$fromEmailFieldOptions .= '<option value="$(general : (__VtigerMeta__) supportName)<$(general : (__VtigerMeta__) supportEmailId)>"