Adapt a314eth to work on PiStorm + A314 emulation

[pistorm] / a314 / files_pi / eth-config-pi / rc.local

iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE  
iptables -A FORWARD -i wlan0 -o tap0 -m state --state RELATED,ESTABLISHED -j ACCEPT  
iptables -A FORWARD -i tap0 -o wlan0 -j ACCEPT