Replace reference to RFC 3280 by reference to newer RFC 5280
diff --git a/library/x509_create.c b/library/x509_create.c
index fb9a839..8cb3a03 100644
--- a/library/x509_create.c
+++ b/library/x509_create.c
@@ -48,7 +48,7 @@
#define ADD_STRLEN( s ) s, sizeof( s ) - 1
-// note: preset tag types as proposed in RFC3280 and widely used
+/* X.509 DN attributes from RFC 5280, Appendix A.1. */
static const x509_attr_descriptor_t x509_attrs[] =
{
{ ADD_STRLEN( "CN" ), MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING },