setup: bump major version

We don't keep this up-to-date in general, but might as well keep
the major version in sync.

Change-Id: I20908005b3b393d384da0ef9342d7c9d094550cb
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/299622


Reviewed-by: Michael Mortensen <mmortensen@google.com>
Tested-by: Mike Frysinger <vapier@google.com>