Fix license header in thrift/test/UnionTest2.thrift
Fix license header in thrift/test/UnionTest2.thrift

Summary: [Thrift] Fix license header in `thrift/test/UnionTest2.thrift`

Reviewed By: yfeldblum

Differential Revision: D16464948

fbshipit-source-id: 28183c6efcbb7efeeeb2c60a2b13ef916ef346a1

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift