message: support: check only the last commit when pushing a new branch
  Otherwise we catch previous errors with DCO that might have crept into
  commit errors. In general, pushing a single commit to a new branch is the
  99%+ case.
diff: @@ -22,9 +22,10 @@ do
  else
  if [ "$REMOTE_SHA" = $DUMMY_SHA ]
  then
  - # New branch. Verify last 15 commits, since verification of the entire
  - # history would take too much time.
  - RANGE="$LOCAL_SHA~15..$LOCAL_SHA"
  + # New branch. Verify the last commit, since this is very likely where the new code is
  + # (though there is no way to know for sure). In the extremely uncommon case in which someone
  + # pushes more than 1 new commit to a branch, CI will enforce full checking.
  + RANGE="$LOCAL_SHA~1..$LOCAL_SHA"
  else
  # Updating branch. Verify new commits.
  RANGE="$REMOTE_SHA..$LOCAL_SHA"
  