net/http/httputil: fix build
net/http/httputil: fix build

TBR=bradfitz
CC=golang-dev
https://codereview.appspot.com/7540043

tv42/old-go,gnanderson/go,gnanderson/go,apparentlymart/golang,gnanderson/go,dsriram/golang,dsriram/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,apparentlymart/golang,dsriram/golang,tv42/old-go,apparentlymart/golang,gnanderson/go,tv42/old-go,apparentlymart/golang,dsriram/golang,gnanderson/go,dsriram/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,pombredanne/go-deleteme,apparentlymart/golang,dsriram/golang,apparentlymart/golang,tv42/old-go,dsriram/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,tv42/old-go,apparentlymart/golang,gnanderson/go,gnanderson/go