bug: RC setting Accounts_AvatarExternalProviderURL not handled properly

[anicoa]

Describe the Bug

RC issue #32824 implements proxying of avatars through the RC server if Accounts_AvatarExternalProviderURL is set in RC admin. This behaviour is better than client side fetching because avatar images can get protected better. Also no client data is submitted to other services this way.

RC ReactNative instead fetches the images directly and does not use the API for this. So there is a different behaviour between RC and ReactNative-App.

Steps to Reproduce

1. Set Accounts_AvatarExternalProviderURL to a valid URL (https://abc.tld/avatar/{username})
2. Watch requests on mobile app using mitmproxy

Expected Behavior

• Avatars fetched from RC server, which fetches avatars from external URL or from cache

Actual Behavior

• Avatars fetched directly from external URL

Rocket.Chat Server Version

8.1.1

Rocket.Chat App Version

4.71.0

Device Name

iPhone 16

OS Version

26.3

Additional Context

This line seems do define the external url. Sould be sufficient to skip setting of external url and just fetch always the avatars from the server. Less code, less complexity, less problems, same behavior than RC web app.