Fixes glitching of inbox label when coming back from background.

The method was not called on the main thread, resulting in rendering
issues.

Signal/src/AppDelegate.m

@@ -174,7 +174,9 @@ static NSString * const kURLHostVerifyPrefix = @"verify";
     dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
         [self protectScreen];
         if ([TSAccountManager isRegistered]) {
-            [[[Environment getCurrent] signalsViewController] updateInboxCountLabel];
+            dispatch_sync(dispatch_get_main_queue(), ^{
+                [[[Environment getCurrent] signalsViewController] updateInboxCountLabel];
+            });
             [TSSocketManager resignActivity];
         }