NO_SYS_TYPES_H isn't defined anywhere, stop using it as a guard

This is a vestige from pre-1.1.0 OpenSSL

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4256)

ssl/ssl_cert.c

diff --git a/ssl/ssl_cert.c b/ssl/ssl_cert.c
index ce4a09f..a0dd878 100644
--- a/ssl/ssl_cert.c
+++ b/ssl/ssl_cert.c
@@ -9,12 +9,9 @@
  */
 
 #include <stdio.h>
+#include <sys/types.h>
 
 #include "e_os.h"
-#ifndef NO_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-
 #include "internal/o_dir.h"
 #include <openssl/lhash.h>
 #include <openssl/bio.h>