Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -32,8 +32,6 @@ build_backend:
 docker_build_test:
   stage: docker
   needs: [build_backend]
-  variables:
-    DOCKER_HOST: "unix:///run/user/1000/docker.sock"
   before_script:
     - docker --version
     - docker info