fixed license header indentation

src/test/java/org/elasticsearch/search/aggregations/bucket/ShardReduceTests.java

@@ -7,7 +7,7 @@
  * not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *     http://www.apache.org/licenses/LICENSE-2.0
+ *    http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an