mod_storage_xmlarchive: Fix return of numeric 'when' from key-value API At some point, 'when' was stored as a timestamp string then as a numeric UNIX timestamp, so both cases needs to be handled, as they are elsewhere. Thanks spec/core_storagemanager_spec.lua

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.