Adapt number formatting to RTL.

// FREEBIE

Signal/src/ViewControllers/ConversationView/MessagesViewController.m

@@ -3903,7 +3903,7 @@ typedef enum : NSUInteger {
 
     // Max out the unread count at 99+.
     const NSUInteger kMaxUnreadCount = 99;
-    _backButtonUnreadCountLabel.text = [@(MIN(kMaxUnreadCount, unreadCount)) stringValue];
+    _backButtonUnreadCountLabel.text = [ViewControllerUtils formatInt:(int) MIN(kMaxUnreadCount, unreadCount)];
 }
 
 #pragma mark 3D Touch Preview Actions