all other charts that related with ceph have the logic
to override the ceph monitor hosts.
but storage class chart only has no logic to override the value.
to use external ceph, it must be able to set manually the ceph host.
Change-Id: Ib788e339606a2f7336a688aa276082503a18b04f
Signed-off-by: Hyunkook Cho <hk0713.cho@samsung.com>