Last night, Infinity Ward issued an update for Call of Duty: Modern Warfare that brought back an April Fool's playlist.Shipment is one of Modern Warfare's best multiplayer maps, its tiny, square playspace a chaotic playground for two teams of five or six players. It was playable in this form around the clock as part of the Shipment 24/7 playlist - something fans had called for for some time. But now Shipment has levelled up - bringing back the wonderful troll update that was Modern Warfare's…