Added V6 support in VN config page... Affected fields - Subnet CIDR, Allocation pool, Gate way, DNS Server, Host rout send value only if ipv4 is there.
Added V6 support in VN config page...
Affected fields
- Subnet CIDR, Allocation pool, Gate way, DNS Server, Host rout send value only
if ipv4 is there.

Change-Id: Ib0b39721d09b4238335db1d725b96e28f77aa9d1

biswajit-mandal/contrail-web-controller,JioCloud/contrail-web-controller,vishnuvv/contrail-web-controller,sbavanasi/contrail-web-controller,varunarya10/contrail-web-controller,skizhak/contrail-web-controller,vishnuvv/contrail-web-controller,sbavanasi/contrail-web-controller,biswajit-mandal/contrail-web-controller,sbavanasi/contrail-web-controller,biswajit-mandal/contrail-web-controller,vishnuvv/contrail-web-controller,manojgn/contrail-web-controller