i386: Unset cannot_destroy_with_object_finalize_yet on "host" model

The class is now safe because the assert(kvm_enabled()) line was
removed by commit e4356010.

Message-Id: <20170119210449.11991-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>