Fix release tag

See merge request !797

.gitlab/ci/.release-container.yml

@@ -5,7 +5,7 @@
         - name: ${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/docker:latest
           alias: docker
     variables:
-      RELEASE_DOCKER_TAG: $CI_COMMIT_REF_SLUG
+      RELEASE_DOCKER_TAG: $CI_COMMIT_TAG
     before_script:
       - apk add git
       - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY