patch 8.2.0449: Vim9: crash if return type is invalid

Problem:    Vim9: crash if return type is invalid. (Yegappan Lakshmanan)
Solution:   Always return some type, not NULL.
diff --git a/src/version.c b/src/version.c
index f1d2f66..0d7b641 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    449,
+/**/
     448,
 /**/
     447,