UDP Packet sent to GitHub for ip address lookup

While I admire the method that is being used to lookup the system's local IP address, I thought I'd try another way and see what you think.  UDP is pretty cheap but I'd feel better if I didn't ping GitHub every time I did something with a downstream library that uses `SysInfo.new`.

The current method (UDP) relies on IPv4 anyway.  So what do you think of the attached change?  Too simple?