rgw: Add explicit messages in radosgw init script

http://tracker.ceph.com/issues/5478 fixes #5478

Signed-off-by: Christophe Courtaut <christophe.courtaut@gmail.com>
Merge pull request #397 from kri5/wip-5478

rgw: Add explicit messages in radosgw init script

Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>