mod_muc_badge: If room has no title use localpart of room's jid (fixes #1767) Without this patch Prosody shows an HTTP 500 error (Lua 5.1) or a "nil" label in the SVG badge (Lua 5.2) if room has no title set.

module:hook("message/host", function (event)
	local stanza = event.stanza;
	if #stanza.tags == 1 and stanza.tags[1].attr.xmlns == "http://jabber.org/protocol/chatstates" then
		return true;
	end
end, -10);