In test environments the default pool size is set to 1, so there is no
redundancy. This causes recent Ceph versions to complain with
HEALTH_WARN as POOL_NO_REDUNDANCY get set.
By disabling the mon_warn_on_pool_no_redundancy option in ceph.conf, the
warning is not reported and the cluster is marked HEALTHY.
See-also: rook/rook#5925
Signed-off-by: Niels de Vos <ndevos@redhat.com>