patch 8.1.0467: cannot build with Mac OS X 10.5

Problem:    Cannot build with Mac OS X 10.5.
Solution:   Change #ifdef into #if. (Akshay Hegde, closes #3022)
diff --git a/src/version.c b/src/version.c
index c416032..def449a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    467,
+/**/
     466,
 /**/
     465,