sync: fix --tags option
sync: fix --tags option

This has been broken since it was added where --tags was actually
the same as --no-tags.  Oddly, it was copied from init where the
logic is correct.

Bug: https://crbug.com/gerrit/12401
Change-Id: I15b89da1a655176a11bebc22573b25c728055328
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/322955
Reviewed-by: Andrew Lamb <bfaeeb019903fd055f46063665bf7aa773e51ed7@google.com>
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@google.com>

couchbasedeps/git-repo,couchbasedeps/git-repo,GerritCodeReview/git-repo,lewixliu/git-repo,lewixliu/git-repo,GerritCodeReview/git-repo