ceph: refuse to failover the arbiter mon on stretch clusters
ceph: refuse to failover the arbiter mon on stretch clusters

Stretch clusters in Ceph do not yet support failing over the arbiter
mon, so we now disable the arbiter mon from failing over. Soon
Ceph will support the arbiter mon failover and we will reenable
this failover feature.

Signed-off-by: Travis Nielsen <a8b474fdb3f77f44446f0ab9ddca8147b09b3a9e@redhat.com>

rook/rook,rook/rook,rook/rook,rook/nfs,rook/nfs,rook/rook,rook/rook,rook/nfs