title: IOS unregisterForRemoteNotifications does not work in airplane mode
body: <p>One of the feature in my app is to unregister user from the remote pushnotification when user logs-out from the app. Is there way I can unregister the app from push notification when user logs out while the device is in airplane(offline) mode?</p>
  
  <p>I tried this code but I still receive notifications when I come back online,
  [[UIApplication sharedApplication] unregisterForRemoteNotifications];</p>
  
  <p>Could some one help how to remove app from notification center when the device is in airplane mode? </p>