Repaint Scrollpane when returning to 2D

Repaint the scrollpane on returning to 2D view from 3D view. This forces
the scrollbar to be repainted rather than show the remnants of the 3D
rendering.

Signed-off-by: Billy Olsen <billy.olsen@gmail.com>

swing/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java

@@ -264,6 +264,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 		rotationSlider.setEnabled(true);
 		scaleSelector.setEnabled(true);
 		scrollPane.revalidate();
+		scrollPane.repaint();
 		revalidate();
 		figureHolder.revalidate();
 		figure.repaint();