Do not fail VMTestObj.create if multiple networks found
Do not fail VMTestObj.create if multiple networks found

VMTestObj.create calls nova.networks.find, which raises an exception if
there are more than one network matching the search criteria (in this
case, more than one network called 'private'). Change to use findAll,
and take the first found network.

Change-Id: I4d0635dbfd8efa37769d1c9a5646179ed74525db

openstack/dragonflow,openstack/dragonflow,FrankDuan/df_code,openstack/dragonflow,FrankDuan/df_code,FrankDuan/df_code