corrected indentation for mongo_url in gitlab-ci

.gitlab-ci.yml

@@ -53,8 +53,8 @@ test:
     # environment: testing
     image: ${DOCKER_IMAGE_NAME}:${DOCKER_TAG}
     variables:
-    ## Setup variable pointin to mongo service
-    MONGO_URL: mongodb://mongodb:27017/frozen
+      ## Setup variable pointin to mongo service
+      MONGO_URL: mongodb://mongodb:27017/frozen
 
     ## When job is started, also start these things
     services: