Description of problem: When setting up a network in the Satellite Web UI, the VLAN ID set in one subnet for ipv4, though optional, causes an error message to display in the Interface settings "VLAN ID is not consistent across subnets".

Version-Release number of selected component (if applicable):

How reproducible:

In Satellite Web UI

Steps to Reproduce:
1. Set VLAN ID in one subnet
2. Leave unset in another subnet
3. Apply settings in Interface settings and receive error

Actual results:

Unable to save interface settings

Expected results:

Be able to save interface settings since the parameter is optional

Additional info: