handle udp send errors
handle udp send errors

fixes #71

"Port should be > 0 and < 65536"

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