Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -15,11 +15,11 @@ docker-build:
   image: docker:cli
   stage: build
   services:
-    - docker:dind
+    - name: docker:dind
+      alias: docker
   variables:
     DOCKER_IMAGE_NAME: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
   before_script:
-    - unset DOCKER_HOST
     - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
   # All branches are tagged with $DOCKER_IMAGE_NAME (defaults to commit ref slug)
   # Default branch is also tagged with `latest`