Fix fixed updater by removing anti-hiccups code

[reosfire]

When I write this code and count myself how much invocations are triggered per second I found that it is ~36

addFixedUpdater((1 / 30f).seconds) {
    debugOverlay.countTick()
}

That happens because sometimes when accum >= 0.75 * time we subtract time and getting accum < 0 (meaning that we need to wait more next time) But then in the code I'm about to delete we just forgetting that fact.

Maybe better way to fix it is by adding && accum > 0 But I actually don't understand what hiccups mean here. And can't see problems which this code solves.