add webtorrent.io to cors whitelist
add webtorrent.io to cors whitelist

For https://github.com/feross/webtorrent-www/issues/23

feross/instant.io,feross/instant.io,corona6/instant.io,bradparks/instant.io,jhiesey/instant.io,corona6/instant.io,feross/instant.io,jhiesey/instant.io,bradparks/instant.io,corona6/instant.io,bradparks/instant.io,jhiesey/instant.io