Better --check compatibility for ceph-fetch-keys role

Carefully chosen "always_run: true" parameters for read-only tasks that
register variables. This enables --check runs (at least on deployed
clusters).

roles/ceph-fetch-keys/tasks/main.yml

@@ -3,6 +3,7 @@
   shell: ls -1 /etc/ceph/*.keyring
   changed_when: false
   register: ceph_keys
+  always_run: true
 
 - name: set keys permissions
   file: