mod_http_xep227: Initialize XEP-0227 XML mod_storage_xep0227 only writes if there is XML already for a user (it uses the presence of an existing <user> element as an indicator that an account exists, although technically this is not something Prosody itself does, so it's a little weird).

This module helps make BOSH and WebSocket connection endpoints
discoverable via the HTTP method described in
[XEP-0156](https://xmpp.org/extensions/xep-0156.html#http).