[Freedombox-pkg-team] Bug#898237: unable to find IP for freedombox

[hjenkins]

Solved.

Added workaround instructions for re-instating a fixed-IP network
configuration after running freedombox-setup at:

https://wiki.debian.org/FreedomBox/Hardware/Debian

Most of the problem was my complete unfamiliarity with NetworkManager,
including not knowing that a lot of things can't be changed through nmtui
but can be changed through nmcli (as of May 2018).