Build OpenLDAP container image used for testing from source

because openshift/openldap-2441-centos7 is no longer available from
Docker Hub

Author: atodorov

.github/workflows/testing.yml

@@ -56,6 +56,12 @@ jobs:
         cat /tmp/kc.env
         echo "**** END DEBUG ****"
 
+    - name: Setup - build OpenLDAP container from source
+      if: matrix.command == 'docker-image'
+      run: |
+        git clone https://github.com/kiwitcms/openldap.git
+        pushd openldap/ && git checkout openldap-2.4.41 && SKIP_SQUASH=1 make build && popd
+
     - name: Sanity test - boot the docker image
       if: matrix.command == 'docker-image'
       run: |