patch 8.0.0429: options test does not always test everything

Problem:    Options test does not always test everything.
Solution:   Fix dependency for opt_test.vim.  Give a message when opt_test.vim
            was not found.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    429,
 /**/
     428,
 /**/