mod_http_oauth2: Strip unknown client metadata Per RFC 7591 > The authorization server MUST ignore any client metadata sent by the > client that it does not understand (for instance, by silently removing > unknown metadata from the client's registration record during > processing). This was previously done but unintentionally removed in 90449babaa48

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.