engine: Simplify host life cycle - removed unneeded SetNonOperational

The following code is uselles, I don't see any reason to set host again to NonOperational
when its status was already NonOperational, the condiiton described in if - it is a bug and
if will occurred will be fixed accordingly

Change-Id: I800beee3d38c3b1036cb82440d67ef744ac5dbae
Signed-off-by: Michael Kublin <mkublin@redhat.com>