Verify that the sig algs extension has been sent for TLSv1.3

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index da57972..dd25934 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -85,7 +85,7 @@
     tls13_final_finish_mac,
     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
-    tls1_alert_code,
+    tls13_alert_code,
     tls1_export_keying_material,
     SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF,
     ssl3_set_handshake_header,