title: Android GCM one device has multiple registrationid
body: <p>I have system that has PHP Server side and Android Client side application. Android sends parameters via webservice and PHP handle the GCM side. PHP sends push notification and before sent, it gets all registrationid from DB. The problem is, same device may have two or more registrationid. Because of this, push notification sent to same devices for two or more times. Is there any solution to handle this problem?</p>