There is a checkbox that says "Use custom URL" - it's even in your screenshot. It is obviously designed to insert something else - a 1x1 pixel for example. That is not a "hack" and as it is there for everyone, it clearly IS the way Google designed it to function.
I suppose you could use a 1x1 pixel as a workaround, but that seems to be more of a hack than the way Google designed it to function.