patch 8.2.3568: ctrl-hat test fails with Athena and Motif

Problem:    Ctrl-hat test fails with Athena and Motif. (Elimar Riesebieter)
Solution:   Run the test only with GTK. (Dominique Pellé, closes #9069)
diff --git a/src/version.c b/src/version.c
index 68372cc..c42cd2a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3568,
+/**/
     3567,
 /**/
     3566,