mod_http_oauth2: Make allowed locales configurable Explicit > Implicit Instead of allowing anything after #, allow only the explicitly configured locales to be used. Default to empty list because using these is not supported yet. This potentially limits the size of the client_id, which is already quite large. Nothing prevents clients from registering a whole client_id per locale, which would not require translation support on this side.

This module helps make BOSH and WebSocket connection endpoints
discoverable via the HTTP method described in
[XEP-0156](https://xmpp.org/extensions/xep-0156.html#http).