strconv: disable issue 2917 test
strconv: disable issue 2917 test

It did in fact break on the darwin/386 builder.
Will investigate later; reopened issue 2917.

R=golang-dev
CC=golang-dev
http://codereview.appspot.com/5654070

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang