docker: add condition to run selinux tasks only on rhel os family
docker: add condition to run selinux tasks only on rhel os family

This fixes the error :

```
The conditional check 'sestatus.stdout != 'Disabled'' failed.
```

that occurs when running on non rhel based system since the
`sestatus` fact is registered only on rhel based distribution.

Signed-off-by: Guillaume Abrioux <30a9df5a0293a6108675377fa1673f7aa713f915@redhat.com>

ceph/ansible-ceph-mon