d/postinst: ensure all ceph state files/dirs have correct owner

d/postinst: ensure all ceph state files/dirs have correct owner

Ceph has a postinst hook that sets the ownership of '/var/lib/ceph/*'
to ceph:ceph (in our case), but misses out on the contents of
'/var/lib/ceph/crash'.

This patch therefore also recursively updates the permissions of
'/var/lib/ceph/crash'.

The change was also proposed upstream [0].

[0]: https://github.com/ceph/ceph/pull/55917

Signed-off-by: Max Carrara <m.carrara@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>