master 1996064996: Fix last change in configure.ac

[Po Lu]

branch: master
commit 199606499606c3f2fc75161da2f286a12cb608c2
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Fix last change in configure.ac
    
    * configure.ac: Test window system against "x11", not "x".
---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 1e66acf52f..721cf16684 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2797,7 +2797,7 @@ gtk3_pkg_errors=
 if test "${opsys}" != "mingw32"; then
   if test "${with_gtk3}" = "yes" || test "${with_gtk}" = "yes" || test 
"$USE_X_TOOLKIT" = "maybe"; then
     GLIB_REQUIRED=2.37.5
-    if test "${window_system}" = "x"; then
+    if test "${window_system}" = "x11"; then
       GTK_REQUIRED=3.10
     else
       GTK_REQUIRED=3.20