Make dhcp test table driven and add another case
Make dhcp test table driven and add another case

Test both null and non-null route gw in particular

nhlfr/virtlet,vefimova/virtlet,nhlfr/virtlet,vefimova/virtlet,vefimova/virtlet,nhlfr/virtlet,Mirantis/virtlet,Mirantis/virtlet,nhlfr/virtlet,vefimova/virtlet