MDEV-33592: Use X509v3 for compatibility with libraries

According to rfc5280, x509v3 was standardised in June 1996.

RusTLS only accepts v3 certificates rejected the v1 default.
(ref:
rustls/webpki#29 (comment))

It seems reasonable that all client libraries can accept v3.

Thanks Austin Bonander for the suggested patch.

vio/viosslfactories.c

@@ -125,6 +125,8 @@ static X509 *vio_gencert(EVP_PKEY *pkey)
   if (!(x= X509_new()))
     goto err;
 
+  if (!X509_set_version(x, X509_VERSION_3))
+    goto err;
   if (!(name= X509_get_subject_name(x)))
     goto err;
   if (!X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC,