wwan_iface_watchdog script for OpenWRT

Watches for disconnected wwan interface and restarts interface.

Copy to /etc/init.d/wwan_iface_watchdog:

scp ./wwan-iface-watchdog root@192.168.1.1:/etc/init.d/

Start service:

/etc/init.d/wwan-iface-watchdog start

Enable service (starts automatically on boot):

/etc/init.d/wwan-iface-watchdog enable