Always draw debug physics with linewidth 1

[idbrii]

Don't let user width leak into physics debug draw. Drawing with a larger line width looks bad (at least it did on my 1080p grid-based game, maybe at super high res you might want a thicker line?).

Currently, users need to set the line width before calling draw. This makes that not necessary. Setup to match how we set colour. If you think it's more useful for users to control the width, go ahead and close.