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: 'Block outgoing stanzas from users'
...

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

This module blocks all outgoing stanzas from a list of users.

Using
=====

Add mod_block_outgoing to the enabled modules in your config file:
``` {.lua}
modules_enabled = {
	-- ...
		"block_outgoing",
	-- ...
}
```

Either in a section for a certain host or the global section define which users and what stanzas to block:
``` {.lua}
block_outgoing_users = { "romeo@example.com", "juliet@example.com" }
block_outgoing_stanzas = { "message", "iq", "presence" }
```

block_outgoing_stanzas defaults to "message" if not specified.