dashboard: set less permissive permissions on dashboard certificate/key

use `0440` instead of `0644` is enough

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
(cherry picked from commit 14f381200d)

roles/ceph-dashboard/tasks/configure_dashboard.yml

@@ -20,7 +20,7 @@
     dest: "/etc/ceph/ceph-dashboard.crt"
     owner: root
     group: root
-    mode: 0644
+    mode: 0440
   when:
     - dashboard_crt
     - dashboard_protocol == "https"
@@ -31,7 +31,7 @@
     dest: "/etc/ceph/ceph-dashboard.key"
     owner: root
     group: root
-    mode: 0644
+    mode: 0440
   when:
     - dashboard_key
     - dashboard_protocol == "https"

roles/ceph-grafana/tasks/configure_grafana.yml

@@ -49,7 +49,7 @@
   copy:
     src: "{{ grafana_key }}"
     dest: "/etc/grafana/ceph-dashboard.key"
-    mode: 0640
+    mode: 0440
   when:
     - grafana_key
     - dashboard_protocol == "https"