[license] Update year to 2021
diff --git a/lib/common/error_private.h b/lib/common/error_private.h
index 71b37b8..9d36e89 100644
--- a/lib/common/error_private.h
+++ b/lib/common/error_private.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
+ * Copyright (c) 2016-2021, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the