Tweak REVERSE settings - change port and increase number games.

Port is changed to 16000, 6112 could cause conflicts and isn't any better than 16000. TODO: let OS decide on a port to bind to.

Also increased gcb_reverse_num since some rooms have more than 20 games hosted at a time. gcb_reverse_num is now at 25, which is higher than the LAN gamelist limit of 20 in case of dropped packets or something.