don't download it. keep it in lbmk.

libreboot moved to codeberg for git hosting,
and i didn't want to keep lugging around an
extra git repo just for one tiny project.

this fixes the build error:

Error: name not set
Usage: ./download gitmodule [name]

when running:

./download all

running "all" runs all scripts under downloads,
one of which was the gitmodule script itself, therefore
being run without argument

gnulib too

gnulib...

osboot is now part of libreboot, and will soon shut down.
libreboot now conforms to osboot policy.