http: fix IP confusion in TestServerTimeouts
http: fix IP confusion in TestServerTimeouts

Don't assume that localhost == 127.0.0.1.
It might be ::1.

R=bradfitzgo
CC=golang-dev
http://codereview.appspot.com/4430055

wesolows/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old