docs(messaging): note iOS data-only delivered after setBackgroundMessageHandler call (#5708)

Author: Brian Meek

docs/messaging/usage/index.md

@@ -111,10 +111,9 @@ The device state and message contents determines which handler will be called:
   as low priority and will ignore it (i.e. no event will be sent). You can however increase the priority by setting the `priority` to `high` (Android) and
   `content-available` to `true` (iOS) properties on the payload.
 
-- On iOS in cases where the message is data-only and the device is in the background or quit, the message will be delayed 8 seconds
-  from the time it arrives on the device until the background message handler registered with setBackgroundMessageHandler is invoked
-  to allow for the applications javascript to be loaded and ready to run [Issue 4144]
-  (https://github.com/invertase/react-native-firebase/pull/4144).
+- On iOS in cases where the message is data-only and the device is in the background or quit, the message will be delayed
+  until the background message handler is registered via setBackgroundMessageHandler, signaling the application's javascript
+  is loaded and ready to run.
 
 To learn more about how to send these options in your message payload, view the Firebase documentation for your [FCM API implementation](https://firebase.google.com/docs/cloud-messaging/concept-options).