Hide email content forcing using to click in a link to visit the portal

New config "hide_email_content" see BT#13475

Author: jmontoyaa

main/inc/lib/notification.lib.php

@@ -371,6 +371,10 @@ public function formatContent($content, $senderInfo)
                 );
                 break;
             case self::NOTIFICATION_TYPE_MESSAGE:
+                $allow = api_get_configuration_value('hide_email_content');
+                if ($allow) {
+                    $content = '';
+                }
                 if (!empty($senderInfo)) {
                     $senderName = api_get_person_name(
                         $senderInfo['firstname'],

main/install/configuration.dist.php

@@ -657,3 +657,6 @@
 
 // Send email notification to admin when a user is created
 //$_configuration['send_notification_when_user_added'] = ['admins' => [1] ];
+
+// Hide email content forcing using to click in a link to visit the portal to check the message
+//$_configuration['messages_hide_mail_content'] = false;