patch 8.0.1099: warnings for GDK calls

Problem:    Warnings for GDK calls.
Solution:   Use other calls for GTK 3 and fix a few problems. (Kazunobu
            Kuriyama)
diff --git a/src/version.c b/src/version.c
index 346d201..689a10e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1099,
+/**/
     1098,
 /**/
     1097,