add regex to parse coverage percentage

.gitlab-ci.yml

@@ -2216,6 +2216,7 @@ coverage:
       - mkdir coverage
       - pwd
       - gcovr -r $CI_PROJECT_DIR -k build -f "src" --print-summary --html coverage/coverage.html --html-details --xml coverage/coverage.xml
+   coverage: /^\s*lines:\s*\d+.\d+\%/
    artifacts:
       paths:
          - coverage/