[Make-wifi-fast] ubuntu 20.4 is out

[Toke Høiland-Jørgensen]

Tried upgrading a VM (from 18.04) through the do-release-upgrade script.
It has a rather amusing notion of what constitutes a helpful prediction
of download times (the VM is on a 10g link):

> You have to download a total of 354 M. This download will take about
> 45 minutes with a 1Mbit DSL connection and about 13 hours with a 56k
> modem.

-Toke