Bug#822595: Raising severity to serious for packages depending on gksu

[Jeremy Bicha]

Control: severity -1 serious
Control: tags -1 -stretch +buster

For the next major stable release of Debian (codenamed "buster"), the
Debian GNOME team plans to default to GNOME on Wayland where gksu does
not work. We do not intend to release "buster" with gksu. Therefore, I
am raising the severity of this issue to serious.

Please drop the dependency on gksu because the Debian GNOME team plans
to remove gksu from Debian soon.

On behalf of the Debian GNOME team,
Jeremy Bicha