.gitlab-ci.yml: update docker image to 20210922.2200
Commit 71b83227128be62c169313e85bb8f339f977ad67 updated the Dockerfile
to be used in CI tests. In order to actually use this new docker image,
update .gitlab-ci.yml to point to the docker image that was created with
the updated Dockerfile.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: Romain Naour <romain.naour@gmail.com>
Tested-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>