engine: Use proper parameters class for CollectVdsNetworkData

The c'tor of CollectVdsNetworkData command expects its parameter
class to derive from CollectHostNetworkDataVdsCommandParameters.

Bug-Url: http://bugzilla.redhat.com/1056501
Change-Id: I9360a0d920e3e71222f9ee062db430d60423cd7c
Signed-off-by: Moti Asayag <masayag@redhat.com>