patch 8.1.1653: ubsan warns for possibly passing NULL pointer

Problem:    Ubsan warns for possibly passing NULL pointer.
Solution:   Skip code when length is zero. (Dominique Pelle, closes #4631)
diff --git a/src/version.c b/src/version.c
index 5061579..03361ca 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1653,
+/**/
     1652,
 /**/
     1651,