Following the license change, modify the boilerplates in external/
[skip ci]
# Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
#
-# Licensed under the OpenSSL license (the "License"). You may not use
+# Licensed under the Apache License 2.0 (the "License"). You may not use
# this file except in compliance with the License. You can obtain a copy
# in the file LICENSE in the source distribution or at
# https://www.openssl.org/source/license.html
