Update README.md

Author: Boris Tacyniak

README.md

@@ -58,25 +58,6 @@ Having a problem? Read the [troubleshooting](./trouble-shooting.md) guide before
 
 The component uses PushNotificationIOS for the iOS part. You should follow their [installation instructions](https://github.com/react-native-community/react-native-push-notification-ios).
 
-When done, modify the following method in the file `AppDelegate.m`:
-```objective-c
-// Called when a notification is delivered to a foreground app.
--(void)userNotificationCenter:(UNUserNotificationCenter *)center
-      willPresentNotification:(UNNotification *)notification
-        withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler
-{
-  // Still call the JS onNotification handler so it can display the new message right away
-  NSDictionary *userInfo = notification.request.content.userInfo;
-  [RNCPushNotificationIOS didReceiveRemoteNotification:userInfo
-                                fetchCompletionHandler:^void (UIBackgroundFetchResult result){}];
-
-  // allow showing foreground notifications
-  completionHandler(UNNotificationPresentationOptionSound | UNNotificationPresentationOptionAlert | UNNotificationPresentationOptionBadge);
-  // or if you wish to hide all notification while in foreground replace it with 
-  // completionHandler(UNNotificationPresentationOptionNone);
-}
-```
-
 ## Android manual Installation
 
 **NOTE: `firebase-messaging`, prior to version 15 requires to have the same version number in order to work correctly at build time and at run time. To use a specific version:**