[LibreRouter] script to redirect dns requests when there is no connection to the internet

Hello guys The greatest problem we have with the installation in Fumaça, Brazil, is that the internet connection is down very often. Ideally, I'd like the users to be redirected to the local server when this happens - not only so that they can use the local applications but also to encourage them to call the company that provides the link and make a complaint. And nodogsplash won't work when the gateway is down. So digging an old post from Gui, I made a small script that is added to the crontab and checks every minute is the network is down. In that case it adds a redirect to the dnsmask config file, which is removed when the connection comes back. It seems to be working in my test network at home. Next thing I'll try with nodogsplash and see it won't break anything. But since my libremesh knowledge is very limited, I'd appreciate if you evaluate if there's any problem with this approach. Thanks! Bruno