message: Fix slider's handle position calculation
diff: @@ -258,7 +258,7 @@ pub fn draw<T>(
  renderer::Quad {
  bounds: Rectangle {
  x: bounds.x,
  - y: rail_y,
  + y: rail_y - 1.0,
  width: bounds.width,
  height: 2.0,
  },
  @@ -273,7 +273,7 @@ pub fn draw<T>(
  renderer::Quad {
  bounds: Rectangle {
  x: bounds.x,
  - y: rail_y + 2.0,
  + y: rail_y + 1.0,
  width: bounds.width,
  height: 2.0,
  },
  @@ -305,8 +305,8 @@ pub fn draw<T>(
  let handle_offset = if range_start >= range_end {
  0.0
  } else {
  - (bounds.width - handle_width) * (value - range_start)
  - / (range_end - range_start)
  + bounds.width * (value - range_start) / (range_end - range_start)
  + - handle_width / 2.0
  };
  renderer.fill_quad(
  