This seems to fix the last missing piece to getting the hotspot stuff
working, at least when it's set up with networkmanager (I haven't tested
other methods, but assume this rule is still needed there too...)
fixes#1198
This fixes DNS when a system is connected to a pmOS device as a hotspot.
The rule is in the default set of firewall rules, instead of a
subpackage.. I think this is OK. I don't believe anything should be
listening on port 53 except when the hotspot is running...