patch 8.1.1533: GUI build fails on Mac

Problem:    GUI build fails on Mac.
Solution:   Change VimClipboard type in non-C file.
diff --git a/src/version.c b/src/version.c
index 146f996..18ef97e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1533,
+/**/
     1532,
 /**/
     1531,