separate hostname.upd6 option for IPv6
separate hostname.upd6 option for IPv6

feross/bittorrent-tracker,jhiesey/bittorrent-tracker,jhiesey/bittorrent-tracker,feross/bittorrent-tracker,prozacchiwawa/bittorrent-tracker,precisit/bittorrent-tracker,LinusU/bittorrent-tracker