Use functions, do not re-implement them

We have the functions reload and redirect which modify window.location.
Use them and do not directly modify window.location so that we have
fewer places of direct window.location modifications and it is easier to
refactor them.

conference.js

 
 import mediaDeviceHelper from './modules/devices/mediaDeviceHelper';
 
-import {reportError} from './modules/util/helpers';
+import { reload, reportError } from './modules/util/helpers';
 
 import UIEvents from './service/UI/UIEvents';
 import UIUtil from './modules/UI/util/UIUtil';
             APP.UI.notifyMaxUsersLimitReached();
             break;
         case ConferenceErrors.INCOMPATIBLE_SERVER_VERSIONS:
-            window.location.reload();
+            reload();
             break;
         default:
             this._handleConferenceFailed(err, ...params);
         APP.UI.addListener(UIEvents.LOGOUT, () => {
             AuthHandler.logout(room).then(url => {
                 if (url) {
-                    window.location.href = url;
+                    UIUtil.redirect(url);
                 } else {
                     this.hangup(true);
                 }