patch 8.2.3409: reading beyond end of line with invalid utf-8 character

Problem:    Reading beyond end of line with invalid utf-8 character.
Solution:   Check for NUL when advancing.
diff --git a/src/version.c b/src/version.c
index 54533dc..0eb6899 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3409,
+/**/
     3408,
 /**/
     3407,