It was out of date; in 1.7 the format changes to 0s.

Change-Id: I2013a1b0951afc5607828f313641b51c74433257
Reviewed-on: https://go-review.googlesource.com/24421Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>