mod_http_admin_api: Ensure freshness of metrics when in manual mode When in manual collection mode, as recommended for Prometheus, collection needs to be triggered manually, or they would be stale, possibly dating from the start of the server. This might vary per metric depending on how and when the metrics are gathered.

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.