patch 8.2.2481: Vim9: confusing error when variable arguments have default

Problem:    Vim9: confusing error when variable arguments have a default
            value.
Solution:   Give a specific error message. (closes #7793)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2481,
 /**/
     2480,
 /**/