osmo-release.sh: Allow user to add extra information to the release commit

Change-Id: Ie25d921dd27fb7653bd616cb2912330964108663
diff --git a/osmo-release.sh b/osmo-release.sh
index 3b50ded..86b41d8 100755
--- a/osmo-release.sh
+++ b/osmo-release.sh
@@ -43,5 +43,6 @@
 dch -r -m --distribution "unstable" ""
 git add debian/changelog
 bumpversion --current-version $VERSION $REL --tag --commit --tag-name $NEW_VER --allow-dirty
+git commit --amend # let the user add extra information to the release commit.
 git tag -s $NEW_VER -f -m "Release v$NEW_VER on $ISODATE."
 echo "Release $NEW_VER prepared, tagged and signed."