Dead Code: THeader::setBestClientType
Dead Code: THeader::setBestClientType

Summary: Get rid of the definition of the unused `setBestClientType` function.

Reviewed By: yfeldblum

Differential Revision: D8046349

fbshipit-source-id: 6ce198174af66f6385948b09de8146f3771c6dba

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