How to reduce top margin in quick launch area?

Thanks Yuri. My setting was already on 0... but, something is a little weird. If I change the value to something large (say 30), click Apply, then change value back to 0 and press Apply, the top margin reduces to a minimum just like I was hoping for. But if I adjust the horizontal width control of the toolbar (manually move the bar to the right of that toolbar to the left or right), then the top margin jumps back to what I showed in the screenshot (without changing the value of the vertical margin setting - it's still on 0).
Seems a bit buggy. I changed the skin of the battery addon to 16.