Loosen minimum screen size detection code for output scale calculation

We return early for screens with physical height reported as ≤ 0mm.

However some extremely dumb screens report a value for their height greater than zero but absurdly small, causing the scale calculator to go ballistic. Theoretically this could happen for widths, too.

Let's loosen the detection to flag a physical screen size as invalid if either its width or height is less than 3mm. There is no screen that can possibly make sense to exist at this physical size given the angular resolution of the human eyeball. And if for some reason it does, 100% scale is fine for it.

BUG: 490777 FIXED-IN: 6.2.0