VMS: Redefine _XOPEN_SOURCE_EXTENDED with the value 1 in apps/ocsp.c

Some versions if the VMS C system header files seem to require this.

Fixes openssl#24466 on release older than 3.3.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from openssl#24471)

(cherry picked from commit 54e9e25)

apps/ocsp.c

@@ -10,8 +10,8 @@
 #include <openssl/opensslconf.h>
 
 #ifdef OPENSSL_SYS_VMS
-# define _XOPEN_SOURCE_EXTENDED/* So fd_set and friends get properly defined
-                                 * on OpenVMS */
+  /* So fd_set and friends get properly defined on OpenVMS */
+# define _XOPEN_SOURCE_EXTENDED 1
 #endif
 
 #include <stdio.h>