mod_auth_oauth_external: Allow different username in PLAIN vs final JID Mastodon for example having email addresses usernames in login, but a different username in the service itself. Thanks to @tcit@social.tcit.fr for the pointer to a usable validation endpoint for Mastodon, allowing this to be tested.

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);