Description of problem:
When the rhevm network on the datacenter is bridgeless it is impossible to add network to VM.

Version-Release number of selected component (if applicable):
rhevm-3.2.0-8.el6ev.noarch

How reproducible:
100%

Steps to Reproduce:
1.Create datacenter (don't add cluster) and change the rhevm network to bridgeless network.
2.Create cluster, add host and add storage.
3.Sync rhevm network using setupNetworks
4.Create new network in the cluster.
5.Create VM and try to add the new network. 
  
Actual results:
Cannot add the network to the VM, the OK button is greyed out.

Expected results:
Should be able to add the network to the VM.