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'

<div id="title">
	<div id="date">###SINCE### - ###TO###</div>
	<div id="roomjid">###JID###</div>
	<div id="links">(join via <a class="component" href="xmpp:###JID###?join">client</a>)</div>
</div>
<div id="calendar">
	<div id="navigation">
		<a class="nav" href="../###PREVIOUS_ROOM###/">&lt;</a>
		<a class="nav" href="../">^</a>
		<a class="nav" href="../###NEXT_ROOM###/">&gt;</a>
	</div>
	<div class="weekday">List of rooms for this component</div>
	<div id="roomList">###ROOMS###</div>
</div>
<div class="topic">###ROOMTOPIC###</div>
<div id="main">
###DAYS_STUFF###
</div>