Fix notification repeat

by adding an undeniable truth
Until now we use the reminderCount as threadId and
 afterwards we updateNotification with a repeat count of always 0

Fixes #3893
Closes #3896

src/org/thoughtcrime/securesms/notifications/MessageNotifier.java

@@ -419,7 +419,7 @@ public class MessageNotifier {
     public void onReceive(Context context, Intent intent) {
       MasterSecret masterSecret  = KeyCachingService.getMasterSecret(context);
       int          reminderCount = intent.getIntExtra("reminder_count", 0);
-      MessageNotifier.updateNotification(context, masterSecret, true, reminderCount + 1);
+      MessageNotifier.updateNotification(context, masterSecret, true, true, reminderCount + 1);
     }
   }