The bug is caused because we already have refs/branch-heads/XXXX locally,
so we don't attempt to fetch it again, even if it has been updated.

This solution is a bit of a hack to make sure that we fetch
refs/branch-heads/*, which is the most common case for this to fail.

Bug: 1070545
Change-Id: Iec7cfff18219794230188e2b9e901c587acd274b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2149849
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>