Run legacy system test in a loop

.gitlab-ci.yml

@@ -313,7 +313,7 @@ stages:
     - *setup_interfaces
   script:
     - cd bin/tests/system
-    - make -j${TEST_PARALLEL_JOBS:-1} -k check V=1
+    - while make check V=1 TESTS=legacy; do true; done
     - if git rev-parse > /dev/null 2>&1; then ( ! grep "^I:.*:file.*not removed$" *.log ); fi
     - '( ! grep -F "grep: warning:" *.log )'
   after_script: