net.unbound: Merge luaunbound and prosody defaults in absence of user config (fixes #1763) (thanks rgd) add_defaults() is supposed to merge 3 tables, the defaults in luaunbound, the defaults from prosody and any config from the prosody config file. In the case where no `unbound={}` has been in the config, it skips over the merge and returns only the prosody built-in defaults. This results in libunbound skipping reading resolv.conf and uses its default behavior of full recursive resolution. Prior to #1737 there were only two tables, the luaunbound defaults and the prosody config, where bypassing the merge and returning the former did the right thing.

-- 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);