Fix license headers in Cassandra related files

Summary:
I might have missed these while doing some recent cassandra code reviews.
Closes https://github.com/facebook/rocksdb/pull/2663

Differential Revision: D5520138

Pulled By: sagar0

fbshipit-source-id: 340930afe9efe03c75f535a1da1f89bd3e53c1f9

include/rocksdb/utilities/debug.h

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 #pragma once
 

java/rocksjni/cassandra_value_operator.cc

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 #include <stdio.h>
 #include <stdlib.h>

java/src/main/java/org/rocksdb/CassandraCompactionFilter.java

-// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
 
 package org.rocksdb;
 

java/src/main/java/org/rocksdb/CassandraValueMergeOperator.java

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 package org.rocksdb;
 

utilities/cassandra/merge_operator.cc

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 #include "merge_operator.h"
 

utilities/cassandra/merge_operator.h

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 #pragma once
 #include "rocksdb/merge_operator.h"

utilities/cassandra/serialize.h

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 /**
  * Helper functions which serialize and deserialize integers

utilities/cassandra/test_utils.cc

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
-// This source code is licensed under the BSD-style license found in the
-// LICENSE file in the root directory of this source tree. An additional grant
-// of patent rights can be found in the PATENTS file in the same directory.
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
 
 #include "test_utils.h"
 

utilities/cassandra/test_utils.h

-// Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under both the GPLv2 (found in the
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).
-// This source code is also licensed under the GPLv2 license found in the
-// COPYING file in the root directory of this source tree.
 
 #pragma once
 #include <memory>