mod_unified_push: Allow additional CORS headers for unified push (fixes #1985) - Request header "TTL" is mandated by the HTTP Push specification RFC 8030: https://datatracker.ietf.org/doc/html/rfc8030#section-5 - Firefox sends "Content-Encoding" with a HTTP form submission, so it is required when using the Unified Push testing tool at https://unifiedpush.org/test_wp.html (with the full URL being delivered by the UP-Example Android app) Adding both headers makes the Unified Push testing tool work from the browser. Resolves: https://issues.prosody.im/1985

local allowed_presence_types = { probe = true, unavailable = true };

function filter_presence(event)
	local stanza = event.stanza;
	local presence_type = stanza.attr.type;
	if presence_type == nil or allowed_presence_types[presence_type] then
		return;
	end
	return true; -- Drop
end

module:hook("pre-presence/bare", filter_presence, 200); -- Client sending
module:hook("presence/bare", filter_presence, 200); -- Client receiving