Don't leak activity context to shortcut badger.

// FREEBIE

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

@@ -504,7 +504,7 @@ public class MessageNotifier {
 
   private static void updateBadge(Context context, int count) {
     try {
-      ShortcutBadger.setBadge(context, count);
+      ShortcutBadger.setBadge(context.getApplicationContext(), count);
     } catch (Throwable t) {
       // NOTE :: I don't totally trust this thing, so I'm catching
       // everything.