Fix enable feedback button check

modules/UI/Feedback.js

      * @param emitter the EventEmitter to associate with the Feedback.
      */
     init: function (emitter) {
-        // Initialise to enabled.
-        this.enabled = true;
-
         // CallStats is the way we send feedback, so we don't have to initialise
         // if callstats isn't enabled.
         if (!APP.conference.isCallstatsEnabled())
             return;
 
-        _showFeedbackButton(true);
+        // If enabled property is still undefined, i.e. it hasn't been set from
+        // some other module already, we set it to true by default.
+        if (typeof this.enabled == "undefined")
+            this.enabled = true;
+
+        _showFeedbackButton(this.enabled);
+
         $("#feedbackButton").click(function (event) {
             Feedback.openFeedbackWindow();
         });

modules/UI/UI.js

 import FollowMe from "../FollowMe";
 import Recorder from "../recorder/Recorder";
 
-
 var eventEmitter = new EventEmitter();
 UI.eventEmitter = eventEmitter;
 
     // Initialise the recorder handler. We're doing this explicitly before
     // calling showToolbar, because the recorder may want to disable all
     // toolbars.
-    new Recorder(APP.conference, UI);
+    new Recorder(APP.conference);
 
     // Once we've joined the muc show the toolbar
     ToolbarToggler.showToolbar();
     UI.setUserAvatar(id, Settings.getEmail());
 
     Toolbar.checkAutoEnableDesktopSharing();
+
     if(!interfaceConfig.filmStripOnly) {
         Feedback.init(eventEmitter);
     }

modules/recorder/Recorder.js

      *
      * @param conference the {conference} which is to transport
      * {Recorder}-related information between participants
-     * @param UI the {UI} which is the source (model/state) to be sent to
-     * remote participants if the local participant is the moderator or the
-     * destination (model/state) to receive from the remote moderator if the
-     * local participant is not the moderator
      */
-    constructor (conference, UI) {
+    constructor (conference) {
         this._conference = conference;
-        this._UI = UI;
 
         // If I am a recorder then I publish my recorder custom role to notify
         // everyone.