patch 8.0.0651: build failure without the auto command feature

Problem:    Build failure without the auto command feature.
Solution:   Add #ifdef. (closes #1782)
diff --git a/src/version.c b/src/version.c
index 684899e..98f4689 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    651,
+/**/
     650,
 /**/
     649,