ceph-osd: Remove ulimit nofile on container start

ceph-osd: Remove ulimit nofile on container start

Even if this improves ceph-disk/ceph-volume performances then it also
impact the ceph-osd process.
The ceph-osd process shouldn't use 1024:4096 value for the max open
files.
Removing the ulimit option from the container engine and doing this kind
of change on the container side [1].

[1] https://github.com/ceph/ceph-container/pull/1497

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1702285
Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>