Fix RangeError from PORT message
Fix RangeError from PORT message

Fix #572

feross/webtorrent,webtorrent/webtorrent,rom1504/webtorrent,jamesliu96/webtorrent,yciabaud/webtorrent,jamesliu96/webtorrent,yciabaud/webtorrent,webtorrent/webtorrent,joshterrill/webtorrent,joshterrill/webtorrent,arestov/webtorrent,feross/webtorrent