[ios] Fix shift+scroll wheel zooming out

When you press shift on macOS, the normal scroll wheel action on a mouse is changed to horizontal scroll instead of vertical

That meant this check never entered, and since translation.y = 0 you always zoom out

Signed-off-by: eisa01 <eisa01@gmail.com>

iphone/Maps/Classes/MapViewController.mm

@@ -938,7 +938,7 @@ NSString *const kAboutSegue = @"Map2About";
     case UIGestureRecognizerStateChanged:
     {
       CGPoint translation = [recognizer translationInView:self.view];
-      if (translation.x == 0 && CGPointEqualToPoint(translation, CGPointZero))
+      if (translation.y == 0)
         return;
       self.userTouchesAction = UserTouchesActionScale;
       static const CGFloat kScaleFactor = 0.9;