Checking out all the paths from HEAD during the last conflicted
step in "git rebase" and continuing would cause the step to be
skipped (which is expected), but leaves MERGE_MSG file behind in
$GIT_DIR and confuses the next "git commit", which has been
corrected.
* pw/rebase-skip-final-fix:
rebase --continue: remove .git/MERGE_MSG
rebase --apply: restore some tests
t3403: fix commit authorship