repo: bump wrapper version

We've rolled quite a number of fixes since the last update, including
a lot of Python 3 improvements.  Lets bump the wrapper version for it.

Change-Id: I6c6c04c3c8241bf8e8bcf26603549ae4595fede8
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/237812
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
Tested-by: Mike Frysinger <vapier@google.com>

repo

@@ -33,7 +33,7 @@ REPO_REV = 'stable'
 # limitations under the License.
 
 # increment this whenever we make important changes to this script
-VERSION = (1, 25)
+VERSION = (1, 26)
 
 # increment this if the MAINTAINER_KEYS block is modified
 KEYRING_VERSION = (1, 2)