changing 127.0.1.1 back to 127.0.0.1 -- will it break anything in Unity?
Solution 1:
Your local machine IS 127.0.0.1. It's the standard IP for the localhost.
Instead, the hostname of your machine resolves to 127.0.1.1.
It should be no problem to change it to anything in the range 127.0.0.0/8 which is reserved for loopbacks.
As long as nothing listens exclusively on 127.0.1.1 you should be safe.
To find if there's something listening on 127.0.1.1:
sudo netstat -tunelp | grep 127.0.1.1