Add the FORGEJO__ prefix as equivalent to GITEA__ when interpreted by
environment-to-ini. It is used when running the Forgejo container like
so:
docker run --name forgejo -e FORGEJO__security__INSTALL_LOCK=true \
-d codeberg.org/forgejo/forgejo:1.18
Signed-off-by: Earl Warren <contact@earl-warren.org>
(cherry picked from commit b4665b0796)
