Add missing debug message

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index e0cdf23..22f8ab7 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -3340,6 +3340,10 @@
             return ret;
         }
         p += output_len;
+    } else {
+        MBEDTLS_SSL_DEBUG_MSG(
+            4, ("early_data not allowed, "
+                "skip early_data extension in NewSessionTicket"));
     }
 
 #endif /* MBEDTLS_SSL_EARLY_DATA */