Add missing check for permissions to delete moderated content

ref https://www.woltlab.com/community/thread/316974-inhalte-in-der-moderation-lassen-sich-ohne-berechtigung-l%C3%B6schen/

Author: BurntimeX

files/lib/system/moderation/queue/report/ConversationMessageModerationQueueReportHandler.class.php

@@ -193,6 +193,12 @@ public function populate(array $queues)
         }
     }
 
+    #[\Override]
+    public function canRemoveContent(ModerationQueue $queue)
+    {
+        return WCF::getSession()->getPermission('mod.conversation.canModerateConversation');
+    }
+
     /**
      * @inheritDoc
      */