[pkg-cinnamon] Bug#891439: muffin: Drop Build-Depends on gconf

[Jeremy Bicha]

Source: muffin
Version: 3.4.1-1
Severity: serious
User: pkg-gnome-maintainers at lists.alioth.debian.org
Usertags: oldlibs gconf
Tags: sid buster patch

Your package appears to have an unused Build-Depends on gconf, but
gconf will be removed from Debian soon. 1[1]

I am not attaching a patch but this seems like a trivial fix.

Also you can drop the gnome-pkg-tools Build-Depends. (For some cinnamon
packages, you will also need to drop the --with gnome option. And if
you switch to debhelper compat 10, you can drop the Build-Depends on
automake, autotools-dev, and dh-autoreconf in addition to the --with
autoreconf option.)

[1] https://lists.debian.org/debian-devel/2018/02/msg00169.html

On behalf of the Debian GNOME team,
Jeremy Bicha