build: fixed use of branch name

Signed-off-by: Philip Windecker <philip.windecker@avenyr.de>

Author: philipwindecker

.github/workflows/antora-build.yml

@@ -38,7 +38,7 @@ jobs:
     - name: Modify site.yml
       working-directory: generator
       run: |
-        sed -i -E "s/(branches\:) \[antora\/base-antora-setup\] \# osi-documentation/\1 [${CI_COMMIT_BRANCH}]/" site.yml
+        sed -i -E "s/(branches\:) \[antora\/base-antora-setup\] \# osi-documentation/\1 [${{CI_COMMIT_BRANCH}}]/" site.yml
         cat site.yml
         sed -i -E "s/cd repo/cd generator/" run-build.sh
         cat run-build.sh