mod_http_oauth2: Reject loopback URIs as client_uri This really should be a proper website with info, https://localhost is not good enough. Ideally we'd validate that it's got proper DNS and is actually reachable, but triggering HTTP or even DNS lookups seems like it would carry abuse potential that would best to avoid.

This module discards typing notifications sent to a bare host JID,
preventing error replies to be sent. These errors are harmless but can
be annoying sometimes if your client shows them prominently.