only add the metadata for servers with at least one repo

Author: bedroge

roles/cvmfs_server_meta_info/tasks/main.yml

@@ -7,6 +7,7 @@
     group: root
     mode: 0644
   become: true
+  when: (cvmfs_repositories | length) > 0
 
 - name: Create meta information for each CVMFS repository
   ansible.builtin.include_tasks: repo_meta_info.yml