Bug#989554: Add argyll dependency

[Age Bosma]

Package: gnome-control-center
Version: 3.38.5-1

This issue applies to many past versions of gnome-control-center as well, but I just ran into it again.

The colour calibration functionality gnome-control-center will happily start the lengthy process of colour testing, only the fail at the end with the error:

"Tools required for calibration are not installed"

This without specifying which tools exactly.

Installing the argyll package solves the issue.

It would therefore be good to have this package included as a dependency.