During the all-star Toby Keith: American Icon tribute show, Luke Bryan made a very special wardrobe decision to honor the late icon. Bryan typically performs wearing a baseball cap, but during appearance at the tribute — which was taped in Nashville last month, and will air Wednesday night (Aug. 28) — Bryan brought out his black cowboy hat in honor of the late, great icon. The Keith hit he sang was “Should’ve Been a Cowboy,” so it’s only fitting that Bryan would don his best cowboy attire for the occasion. But the hat had another meaning, too. He chose it in honor of his late sister, he explai…