Ability to change the GUI port

[yubiuser]

Just for your info:

Help FTL not installed

It used to be that port 80 was a hard requirement for Pi-hole, though that it less relevant these days. The reason being is that we used to by default (though, it is still possible with some reconfiguring) serve a block page as a 404 for all Pi-holed requests, by returning the IP address of the Pi-hole and the rest of the url (e.g http://pi-hole-ip/images/advert.jpg, which doesn't exist, so 404 is returned) But since the rise of https, the block page has become less relevant. The plan for v6.0…