Disabled PUSH-registration on non-FFOS

Closes #398

app/js/services.js

@@ -1,5 +1,5 @@
 /*!
- * Webogram v0.2.5 - messaging web application for MTProto
+ * Webogram v0.2.8 - messaging web application for MTProto
  * https://github.com/zhukov/webogram
  * Copyright (C) 2014 Igor Zhukov <igor.beatle@gmail.com>
  * https://github.com/zhukov/webogram/blob/master/LICENSE
@@ -3534,7 +3534,7 @@ angular.module('myApp.services', [])
     if (registeredDevice) {
       return false;
     }
-    if (navigator.push) {
+    if (navigator.push && Config.Navigator.ffos && Config.Modes.packed) {
       var req = navigator.push.register();
 
       req.onsuccess = function(e) {