cephadm: avoid trigger old podman bug

cephadm: avoid trigger old podman bug

This ticket seems to suggest that (1) the root cause is related to an
exec that is orphaned and screws up the container state (due to, e.g., ssh
dropping, or a timeout), (2) -f may be needed, sometimes, to recover, and
(3) newer versions fix it.

  https://github.com/containers/libpod/issues/3226

Way back in 26f9fe54cb635cbcd8f74849d6fa3528cdf5d755 we found that using
-f the first time around was a Bad Idea, so we'd rather avoid this.

Instead, just avoid triggering the bug.

Signed-off-by: Sage Weil <sage@redhat.com>