mod_http_admin_api: metrics: Filter out a value that is commonly nan at startup The upload bytes count is typically nan at startup, which cannot legally be encoded in JSON. I haven't assessed whether any other metrics might emit nan under other circumstances, but this fixes the most visible issue right now.

module:hook("authentication-success", function (event)
	local session = event.session;
	local sasl_handler = session and session.sasl_handler;
	local log = session and session.log or module._log
	log("info", "Authenticated with %s", sasl_handler and sasl_handler.selected or "legacy auth");
end);