mod_unified_push: Fix push error handling (fixes #2000) Use the error object that send_iq() passes as an argument to it's reject callback instead of attempting and failing to do the parsing in the callback itself.

% 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`