ShapePath with strokeWidth < 2.5 do not produce rounded caps nor joins with OpenGL renderer

In QTriangulatingStroker::process there is a check to test if stroke width is less than 2.5 and if so, it unsets rounded cap and join.

With 100% scale factor this is probably fine, but at 300%, I would expect there to be enough pixels to do this rounding.

Software renderer and nvidia specific renderer do render the caps.