Revert "deja-dup: add dconf"

This reverts commit 84698bab23d02393ab24e38a1e3ddb3d9d952861.

dconf is already there from wrapGAppsHook.

pkgs/applications/backup/deja-dup/default.nix

···
 , libgpgerror
 , json-glib
 , duplicity
-, dconf
 }:
 
 stdenv.mkDerivation rec {
···
     libhandy_0
     libgpgerror
     json-glib
-    dconf
   ];
 
   mesonFlags = [