handle s3rver launched with ip other than localhost
handle s3rver launched with ip other than localhost

(for example docker environment), now we don't only test for ctx.hostname being 127.0.0.1, but any ip
other when using docker, you would end up with an ip in for example 172.12.0.6, and vhost.js would
have erroneously replaced ctx.path by  `/undefined/$bucketname`
jamhall/s3rver,rockmacaca/s3rver,jamhall/s3rver