gnome3: also pass self to overridePackages function

pkgs/desktops/gnome-3/3.16/default.nix

···
       self = self_ // overrides;
       self_ = with self; {
 
-  overridePackages = f: pkgsFun (f self);
+  overridePackages = f:
+    let newself = pkgsFun (f newself self);
+    in newself;
 
   callPackage = pkgs.newScope self;