patch 8.0.0437: packadd test does not fully work

Problem:    The packadd test does not create the symlink correctly and does
            not test the right thing.
Solution:   Create the directory and symlink correctly.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    437,
 /**/
     436,
 /**/