use the correct uploader name

{{cookiecutter.project_slug}}/.gitlab-ci.yml

@@ -72,7 +72,7 @@ undeploy test version:
     DEPLOY_PATH: "test_builds/$CI_COMMIT_REF_NAME"
   script:
     - mkdir empty/
-    - "rsync -rlv --delete empty/ solidstate@tnw-tn1.tudelft.net:$DEPLOY_PATH"
+    - "rsync -rlv --delete empty/ {{cookiecutter.project_slug}}@tnw-tn1.tudelft.net:$DEPLOY_PATH"
   environment:
     name: $CI_COMMIT_REF_NAME
     action: stop