ar71xx: WDR4300: Fixed default VLAN order

Reordered the VLANs so the LAN ports are set to VLAN 1 and the WAN port is set to VLAN 2, as in the other routers in the config file. Moreover, this model had this VLAN mapping in OpenWRT Chaos Calmer. It seems that the VLAN were switched when fixing a bug in the port mapping ( OpenWRT changeset 47799 )

Signed-off-by: David Pinilla Caparrós <dpinitux@gmail.com>