cmd/gitmirror: fix incorrect ptr logic in test
cmd/gitmirror: fix incorrect ptr logic in test

Change-Id: If6cd289b3dd26dcc7496f331436227014f54bb74
Reviewed-on: https://go-review.googlesource.com/64730
Reviewed-by: Andrew Bonventre <682ad9f487f614f19e8b7cc5d340bdc8e1c1b128@golang.org>

golang/build,golang/build,golang/build,golang/build