common: replace shell module

there is no need to use `shell` in these tasks. Let's use `command`.

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>

roles/ceph-facts/tasks/facts.yml

@@ -106,7 +106,7 @@
     - not rolling_update | bool
   block:
   - name: generate cluster fsid
-    shell: "{{ discovered_interpreter_python }} -c 'import uuid; print(str(uuid.uuid4()))'"
+    command: "{{ discovered_interpreter_python }} -c 'import uuid; print(str(uuid.uuid4()))'"
     register: cluster_uuid
     delegate_to: "{{ groups[mon_group_name][0] }}"
     run_once: true

roles/ceph-mon/tasks/deploy_monitors.yml

@@ -10,7 +10,7 @@
   when: ceph_current_status.fsid is defined
 
 - name: generate monitor initial keyring
-  shell: >
+  command: >
     {{ discovered_interpreter_python }} -c "import os ; import struct ;
     import time; import base64 ; key = os.urandom(16) ;
     header = struct.pack('<hiih',1,int(time.time()),0,len(key)) ;