Keeping the dockerfiles/Dockerfile.cross image at 1.13, as we don't
have more current versions of that image. However, I don't think it's
still used, so we should remove it.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit a477a727fc)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>