try to fix container registry

- get commands right

.gitlab-ci.yml

@@ -87,6 +87,9 @@ clean_docker_registry:
     - docker-privileged
   when: always
   image: docker:19.03.12
-  script:
+  services:
+    - docker:19.03.12-dind
+  before_script: 
     - docker login -u $GPT_REGISTRY_USER -p $GDT_REGISTRY_PASSWORD $CI_REGISTRY
+  script:
     - docker image -a