patch 8.2.3526: tests have clumsy check for X11 based GUI

Problem:    Tests have clumsy check for X11 based GUI.
Solution:   Add CheckX11BasedGui.
diff --git a/src/version.c b/src/version.c
index ba4a990..3b78cc8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3526,
+/**/
     3525,
 /**/
     3524,