patch 9.0.0615: using reduce() on a list from range() is a bit slow

Problem:    Using reduce() on a list from range() is a bit slow.
Solution:   Avoid materializing the list.
diff --git a/src/version.c b/src/version.c
index 623feda..5bf2999 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    615,
+/**/
     614,
 /**/
     613,