Remove a TLS1.3 TODO that is now completed

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2259)

test/ssl-tests/06-sni-ticket.conf.in

@@ -19,7 +19,6 @@ our @tests = ();
 
 #Note: MaxProtocol is set to TLSv1.2 as session tickets work differently in
 #TLSv1.3.
-#TODO(TLS1.3): Implement TLSv1.3 style session tickets
 sub generate_tests() {
     foreach my $c ("SessionTicket", "-SessionTicket") {
         foreach my $s1 ("SessionTicket", "-SessionTicket") {