Implement QemuIoInteractive to test nbd-server-remove command when
there are active connections.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180119135719.24745-5-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>