Description of problem:
The vnics subtab is not invalidating and so if going from a VM with 2 vnics to a VM with 1 vnic the subtab will still show the 2nd vnic of the first VM.

Version-Release number of selected component (if applicable):
oVirt Engine Version: 3.3.0_master

How reproducible:
100%

Steps to Reproduce:
1. Create two VMs
2. Add a second vnic to the second VM
3. Click on the second VM, click on the Network Interfaces subtab
4. Click on the first VM

Actual results:
First VM now shows that it has two vnics. The extra vnic vanishes after 10~ seconds

Expected results:
It should only have one