LICENSE: Restore original Apache license

LICENSE

-Copyright 2019 The TensorFlow Authors.  All rights reserved.
 
                                  Apache License
                            Version 2.0, January 2004
@@ -188,7 +187,7 @@ Copyright 2019 The TensorFlow Authors.  All rights reserved.
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2017, The TensorFlow Authors.
+   Copyright [yyyy] [name of copyright owner]
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.