Dead Code: wangle::BlockingQueue
Dead Code: wangle::BlockingQueue

Summary: [Wangle] Dead Code: `wangle::BlockingQueue`, which is but an alias to `folly::BlockingQueue`.

Reviewed By: jsedgwick

Differential Revision: D6120200

fbshipit-source-id: bd9efa24180abf4655a8798237d3396ca3f296cf

facebook/wangle,facebook/wangle,facebook/wangle