ceph-nfs: fixed with_items

If we do this in one line we get the error described in #3968

fixes #3968

Signed-off-by: Bruceforce <markus.greis@gmx.de>

roles/ceph-nfs/tasks/pre_requisite_non_container.yml

@@ -51,7 +51,8 @@
         owner: "ceph"
         group: "ceph"
         mode: "0600"
-      with_items: { name: "/var/lib/ceph/bootstrap-rgw/{{ cluster }}.keyring", copy_key: "{{ nfs_obj_gw }}" }
+      with_items:
+        - { name: "/var/lib/ceph/bootstrap-rgw/{{ cluster }}.keyring", copy_key: "{{ nfs_obj_gw }}" }
       when: item.copy_key|bool
 
     - name: nfs object gateway related tasks