various: Improve error reporting if missing file server module on 0.12 If there is some error loading net.http.files then it would be swallowed by the pcall and then it would proceed to trying mod_http_files, which might cause unexpected behavior on 0.12 Ref #1765

---
summary: External Service Discovery
...

This module implementing [XEP-0215] is included with Prosody 0.12 but made available here for older versions.

Documentation is available on the [Prosody site][doc:modules:mod_external_services].