mod_http_oauth2: Calculate client secret expiry in registration response Not actually the client_secret that expires, but the client_id JWT. Returning '0' indicating no expiry was incorrect unless JWT expiry is turned off, which we check for now.

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.