Fixed: Transpiling of for-each in notification.js leads to error due to array modifications

lib/notification.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 313 matching lines @@
 
   /**
    * Notifies listeners about interactions with a notification
    * @param {String} id notification ID
    * @param {Boolean} approved indicator whether notification has been approved or not
    */
   triggerQuestionListeners: function(id, approved)
   {
     if (!(id in listeners))
       return;
-    for each (let listener in listeners[id])
+    let questionListeners = listeners[id];
+    for each (let listener in questionListeners)
       listener(approved);
   }
 };
 Notification.init();