Duplicate completionHandler on push presentation.

With respect to:

- (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler API_AVAILABLE(ios(10.0), macos(10.14))
{
    COUNTLY_LOG(@"userNotificationCenter:willPresentNotification:withCompletionHandler:");
    COUNTLY_LOG(@"%@", notification.request.content.userInfo.description);

    if (!self.doNotShowAlertForNotifications)
    {
        NSDictionary* countlyPayload = notification.request.content.userInfo[kCountlyPNKeyCountlyPayload];
        NSString* notificationID = countlyPayload[kCountlyPNKeyNotificationID];

        if (notificationID)
            completionHandler(UNNotificationPresentationOptionAlert);
    }

    id<UNUserNotificationCenterDelegate> appDelegate = (id<UNUserNotificationCenterDelegate>)CLYApplication.sharedApplication.delegate;

    if ([appDelegate respondsToSelector:@selector(userNotificationCenter:willPresentNotification:withCompletionHandler:)])
        [appDelegate userNotificationCenter:center willPresentNotification:notification withCompletionHandler:completionHandler];
    else
        completionHandler(UNNotificationPresentationOptionNone);
}

It appears that completionHandler is invoked twice, once with UNNotificationPresentationOptionAlert (if not doNotShowAlertForNotifications) and once with UNNotificationPresentationOptionNone.  Perhaps the intention was to return inside the `if`, though then the appDelegate doesn't get a chance to willPresentNotification.