mod_http_oauth2: Reference grant by id instead of value Fixes that the grant got mutated on use of refresh token, notably it would gain 'id' and 'jid' properties set there by mod_tokenauth. Previously also the secret token that we should not be remembering.

This module produces more detailed HTTP logs for Prosodys built-in HTTP
server. The format is similar to that of Apache and go into Prosodys
normal logs at the `info` level.