Tests: fixed TLSv1.3 session reuse in stream_ssl_certificate.t.

See 8b122b35703b for details.  This is a missing part for stream tests.

stream_ssl_certificate.t

diff --git a/stream_ssl_certificate.t b/stream_ssl_certificate.t
index a4388e8..1655b65 100644
--- a/stream_ssl_certificate.t
+++ b/stream_ssl_certificate.t
@@ -159,7 +159,7 @@
 
 # session reuse
 
-my ($s, $ssl) = get_ssl_socket('default', 8080);
+my ($s, $ssl) = get('default', 8080);
 my $ses = Net::SSLeay::get_session($ssl);
 
 like(get('default', 8080, $ses), qr/:r/, 'session reused');
@@ -183,7 +183,8 @@
 	my ($s, $ssl) = get_ssl_socket($host, $port, $ctx) or return;
 	my $r = Net::SSLeay::read($ssl);
 	$s->close();
-	return $r;
+	return $r unless wantarray();
+	return ($s, $ssl);
 }
 
 sub cert {