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.
diff --git a/src/version.c b/src/version.c
index 870b66b..413c2c1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    437,
+/**/
     436,
 /**/
     435,