cmd/dist: revert an accidental change to the optimization setting
cmd/dist: revert an accidental change to the optimization setting

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/38130043

apparentlymart/golang,apparentlymart/golang,apparentlymart/golang,apparentlymart/golang,apparentlymart/golang,apparentlymart/golang,apparentlymart/golang