3d-viewer: Remove duplicate call

Simplify is called by GetBoardPolygonOutlines(), it does not need to be
called a second time.

3d-viewer/3d_canvas/cinfo3d_visu.cpp

@@ -463,9 +463,6 @@ void CINFO3D_VISU::createBoardPolygon()
         wxLogMessage( errmsg );
     }
 
-    // Be sure the polygon is strictly simple to avoid issues.
-    m_board_poly.Simplify( SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
-
     Polygon_Calc_BBox_3DU( m_board_poly, m_board2dBBox3DU, m_biuTo3Dunits );
 }