devserver binds to network as well as localhost

Created by: talkingtab

Instead of opening a port on the localhost only, create-react-app now binds to the network as well. On a new instance when I run yarn start I get:

You can now view foo in the browser. Local: http://localhost:3000/ On Your Network: http://xxx.138.90.222:3000/

I use ufw to close ports, but this change from previous versions seems like it could potentially cause problems.