Update .gitlab-ci.yml

Former-commit-id: a750fa4b

.gitlab-ci.yml

@@ -15,6 +15,7 @@ before_script:
    # make toil workdir
    - mkdir workdir
    - mkdir logs
+   - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
 
 after_script:
   - echo "All done"
@@ -34,7 +35,6 @@ push_docker_tags:
     - tags
   script: 
     - docker tag lofareosc/prefactor-ci:latest $CI_REGISTRY/prefactor-ci:$CI_COMMIT_REF_NAME
-    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
     - docker push $CI_REGISTRY/prefactor-ci:$CI_COMMIT_REF_NAME
 
 push_docker_master: