mod_roster_command: Fix subscription when the "user JID" is a bare domain. Do not attempt to update the roster when the user is bare domain (e.g. a component), since they don't have rosters and the attempt results in an error: $ prosodyctl mod_roster_command subscribe proxy.example.com contact@example.com xxxxxxxxxxFailed to execute command: Error: /usr/lib/prosody/core/rostermanager.lua:104: attempt to concatenate local 'username' (a nil value) stack traceback: /usr/lib/prosody/core/rostermanager.lua:104: in function 'load_roster' /usr/lib/prosody/core/rostermanager.lua:305: in function 'set_contact_pending_out' mod_roster_command.lua:44: in function 'subscribe'

---
summary: HTTP favicon
...

Introduction
============

This simple module serves a `favicon.ico` from prosodys HTTP server and
nothing else.

Configuring
===========

Simply load the module. The icon can be replaced by adding a `favicon`
option to the config.

    modules_enabled = {
        ...
        "favicon";
    }

    favicon = "/path/to/my-favicon.ico" -- Override the built in one

Compatibility
=============

  ------- --------------
  trunk   Works
  0.9     Works
  0.8     Doesn't work
  ------- --------------