patch 8.1.0791: a few compiler warnings on VMS

Problem:    A few compiler warnings on VMS.
Solution:   Remove type cast.  Adjust #ifdef. (Zoltan Arpadffy)
diff --git a/src/version.c b/src/version.c
index 8d2050f..f33f850 100644
--- a/src/version.c
+++ b/src/version.c
@@ -792,6 +792,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    791,
+/**/
     790,
 /**/
     789,