[chg] test co CI_COMMIT_BRANCH

Author: fkalweit

.gitlab-ci.yml

@@ -54,6 +54,11 @@ test-antora-build:
     - git checkout $CI_COMMIT_REF_NAME
     - git show --summary
     - git show-ref --head
+    - - if [ "$CI_COMMIT_BRANCH" != "" ]; then
+    -   git checkout $CI_COMMIT_BRANCH
+    - fi
+    - git show --summary
+    - git show-ref --head
     - *npm_install
     - cd antora-ui
     - gulp bundle