Update copyright year

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16534)

(cherry picked from commit 54d987b92ce57c1cc38c6d9b6bf879b003f4cbd4)

ssl/ssl_stat.c

diff --git a/ssl/ssl_stat.c b/ssl/ssl_stat.c
index 32bc432..f2316f7 100644
--- a/ssl/ssl_stat.c
+++ b/ssl/ssl_stat.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
  * Copyright 2005 Nokia. All rights reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use