ceph.py: the journal component does not current work with restart

Removing for the time being.

Signed-off-by: Samuel Just <sam.just@inktank.com>
ceph.py: set up ctx.disk_config outside of the loop

Signed-off-by: Samuel Just <sam.just@inktank.com>
ceph_manager: mount_osd_data expects osd as a str

Signed-off-by: Samuel Just <sam.just@inktank.com>