Issue 5952 - Clicking Cancel in the issue reporter doesn't close the tab

messageResponder.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 189 matching lines @@
 
     if (message.what == "features")
     {
       return {
         devToolsPanel: info.platform == "chromium" ||
                        info.application == "firefox" &&
                        parseInt(info.applicationVersion, 10) >= 54
       };
     }
 
+    if (message.what == "senderId")
+      return sender.page.id;
+
     return info[message.what];
   });
 
   port.on("app.listen", (message, sender) =>
   {
     getListenerFilters(sender.page).app = message.filter;
   });
 
   port.on("app.open", (message, sender) =>
   {
@@ skipping 233 matching lines @@
     if (message.url)
       subscriptions = [Subscription.fromURL(message.url)];
 
     for (let subscription of subscriptions)
     {
       if (subscription instanceof DownloadableSubscription)
         Synchronizer.execute(subscription, true);
     }
   });
 })(this);