Fix MP5 iron sights

Unlike other guns in Bodycam, the MP5's iron sights aren't lined up properly. The back sight is lower than it should be, causing it to look weird and all the bullets go above the tip of the front iron sight. First image: First shot accuracy test: Aiming in the center of the "O" but bullet lands far above the "O" 2nd image: Full-auto shooting test: Aiming significantly lower than where every bullet lands, even at the beginning of the mag dump. 3rd image: I was dragging my mouse down in order to show how the iron sights *should* be lined up.