vglserver_config: Fix compat. issues with SUSE 16

SUSE 16 uses /usr/etc/X11/xdm/Xsetup rather than /etc/X11/xdm/Xsetup as
the SDDM display command and LightDM greeter setup script.

Author: dcommander

ChangeLog.md

@@ -66,6 +66,9 @@ attempting to run a GLX application using the EGL back end and `vglrun -nodl`.
 14. Fixed an issue whereby the VirtualGL Configuration dialog did not pop up if
 the Num Lock key was on.
 
+15. `vglserver_config` now works properly with SUSE Linux Enterprise/openSUSE
+Leap 16.
+
 
 3.0.2
 =====

server/vglserver_config

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 # Copyright (C)2007 Sun Microsystems, Inc.
-# Copyright (C)2009-2014, 2016, 2018-2020, 2022-2023 D. R. Commander
+# Copyright (C)2009-2014, 2016, 2018-2020, 2022-2023, 2026 D. R. Commander
 #
 # This library is free software and may be redistributed and/or modified under
 # the terms of the wxWindows Library License, Version 3.1 or (at your option)
@@ -678,6 +678,7 @@ EOF
 		/usr/local/kde4/share/config/kdm/Xsetup \
 		/etc/sddm/Xsetup \
 		/usr/share/sddm/scripts/Xsetup \
+		/usr/etc/X11/xdm/Xsetup \
 		/etc/mdm/Init/Default; do
 		if [ -f $file -a ! -h $file ]; then
 			delvglgenkey $file
@@ -894,6 +895,7 @@ EOF
 		/usr/local/kde4/share/config/kdm/Xsetup \
 		/etc/sddm/Xsetup \
 		/usr/share/sddm/scripts/Xsetup \
+		/usr/etc/X11/xdm/Xsetup \
 		/etc/mdm/Init/Default; do
 		if [ -f $file -a ! -h $file ]; then
 			addvglgenkey $file