http tracker: support multiple info_hash scrapes
http tracker: support multiple info_hash scrapes

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