mod_roster: pass correct username to roster-item-removed
The other invocations use it that way, and the only listener in trunk
which uses it (in mod_presence) expects it that way.
Passing the username of the JID from the removed entry causes incorrect
unavailable presence stanzas to be sent, allegedly kicking people off
MUCs.
Fixes #1121.
-- XEP-0307: Unique Room Names for Multi-User Chat
local st = require "util.stanza";
local unique_name = require "util.id".medium;
module:add_feature "http://jabber.org/protocol/muc#unique"
module:hook("iq-get/host/http://jabber.org/protocol/muc#unique:unique", function(event)
local origin, stanza = event.origin, event.stanza;
origin.send(st.reply(stanza)
:tag("unique", {xmlns = "http://jabber.org/protocol/muc#unique"})
:text(unique_name():lower())
);
return true;
end,-1);