File gdm-gdmsetup-rootonly.patch of Package gdm

--- gui/gdmsetup.desktop.in.in
+++ gui/gdmsetup.desktop.in.in
@@ -5,6 +5,7 @@
 _Comment=Configure the login window (GNOME Display Manager)
 TryExec=@sbindir@/gdmsetup
 Exec=gdmsetup
+X-KDE-RootOnly=true
 Icon=gdm-setup
 StartupNotify=true
 Terminal=false