Update the version of the commits DB, so it gets regenerated

After the fix from adb39df6bb.

Fixes #785

bugbug/repository.py

@@ -33,7 +33,7 @@ COMMITS_DB = "data/commits.json"
 db.register(
     COMMITS_DB,
     "https://index.taskcluster.net/v1/task/project.relman.bugbug.data_commits.latest/artifacts/public/commits.json.zst",
-    1,
+    2,
     ["commit_experiences.pickle.zst"],
 )