A number of photos posted to Vietnamese blog tinthe.vn allege to show off Apple’s upcoming second-generation iPad Air. The shots show a thinner iPad Air — reportedly 7mm thin, about the same as the new iPhones — with Touch ID and recessed volume controls. Curiously, the photos also show no mute switch on the new iPad, though what will actually happen to the switch remains ambiguous. Speculation that the switch was removed to save space makes…