Fix wxWidgets 2.8 compatibility

    wxStaticText* text;

    wxSize        BoxMatrixMinSize;

    // Try to know the size of bitmaps used in drc matrix

    wxBitmap      bitmap = KiBitmap( ercwarn_xpm );

    wxSize        bitmap_size = bitmap.GetSize();

    bitmap_size.x += 5;

    bitmap_size.y += 8;    // Add a margin around the bitmap

    // Try to know the size of bitmap button used in drc matrix

    wxBitmapButton * dummy = new wxBitmapButton( m_PanelERCOptions, wxID_ANY,

                                              KiBitmap( ercerr_xpm ) );

    wxSize bitmap_size = dummy->GetSize();

    delete dummy;

    if( !DiagErcTableInit )

    {