mod_storage_s3: Fix storing archives for host itself (e.g. mod_audit) Fixes error due to path constructor trying to do string.gsub(nil) with missing username or with fields.

% Prosody log format for lnav

This is a format definition that allows <https://lnav.org/> to better
handle Prosody logs.

Install it using `lnav -i ./prosody.json`