tool: show if server sent SCT staple

Change-Id: I02e33a89345eaa935c06e3e6d88f7611049f1387
Reviewed-on: https://boringssl-review.googlesource.com/13884
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

tool/transport_common.cc

@@ -285,6 +285,11 @@ void PrintConnectionInfo(const SSL *ssl) {
     size_t ocsp_staple_len;
     SSL_get0_ocsp_response(ssl, &ocsp_staple, &ocsp_staple_len);
     fprintf(stderr, "  OCSP staple: %s\n", ocsp_staple_len > 0 ? "yes" : "no");
+
+    const uint8_t *sct_list;
+    size_t sct_list_len;
+    SSL_get0_signed_cert_timestamp_list(ssl, &sct_list, &sct_list_len);
+    fprintf(stderr, "  SCT list: %s\n", sct_list_len > 0 ? "yes" : "no");
   }
 
   // Print the server cert subject and issuer names.