engine: NetworkQoS should be sent to vdsm on nic hotplug

The patch assures the network QoS parameters are being
sent to vdsm as entries of the specParams map.

Change-Id: Ic6fc4a7cd517bfea733cd2e89877ab9d8c34c78e
Bug-Url: https://bugzilla.redhat.com/1002281
Signed-off-by: Moti Asayag <masayag@redhat.com>