VMS config: Typo fix, as -> AS

This typo prevented ia64 assembler to be compiled on VMS
Reviewed-by: NTim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7700)

(cherry picked from commit 04375857cf4971460c473fa44bef86351f2177fe)

Configurations/10-main.conf

@@ -1782,7 +1782,7 @@ my %targets = (
     },
     "vms-ia64" => {
         inherit_from     => [ "vms-generic",
-                              sub { vms_info()->{as}
+                              sub { vms_info()->{AS}
                                         ? asm("ia64_asm")->() : () } ],
         bn_ops           => "SIXTY_FOUR_BIT RC4_INT",
         pointer_size     => "",