engine: Update vnic profile id when adding vm from snapshot

Adding vm from snapshot loads the vm configuration from the
OVF which requires resolving the vnic profile id by the
network name and the vnic profile name.

Change-Id: Ie3057590b59fc7281b1c49fb9b94144999bcb471
Bug-Url: https://bugzilla.redhat.com/1003523
Signed-off-by: Moti Asayag <masayag@redhat.com>