Sync ar7 default network configuration with latest firewall and network settings, thanks sn9

SVN-Revision: 12444

target/linux/ar7/base-files/etc/config/network

@@ -7,12 +7,12 @@ config interface loopback
 	option netmask	255.0.0.0
 
 config interface lan
+	option type	bridge
 	option ifname	eth0
 	option proto	static
 	option ipaddr	192.168.1.1
 	option netmask	255.255.255.0
-
-
+	option nat	1
 
 ## Example for ATM bridging.
 ## Useful for PPPoE or IP over ATM. Will create 'nas${unit}'