Bugfix. Don't set fake nick...

when creating occupant from affiliation change stanza.

This means that when a presence for that occupant arrives, a duplicate
occupant is created (presumably because the original can't be find due
to the wrong nick being set).

src/headless/plugins/muc/muc.js

@@ -394,7 +394,6 @@ const ChatRoomMixin = {
                 from,
                 type,
                 affiliation,
-                'nick': Strophe.getNodeFromJid(jid),
                 'states': [],
                 'show': type == 'unavailable' ? 'offline' : 'online',
                 'role': item.getAttribute('role'),