Fix the minimum size in qt-display-mode 1 to show all the cone.

(cherry picked from commit fce957a4)
Signed-off-by: Christophe Mutricy <xtophe@videolan.org>

modules/gui/qt4/components/interface_widgets.cpp

@@ -181,7 +181,7 @@ QSize VideoWidget::sizeHint() const
  **********************************************************************/
 #define ICON_SIZE 128
 #define MAX_BG_SIZE 400
-#define MIN_BG_SIZE 64
+#define MIN_BG_SIZE 128
 
 BackgroundWidget::BackgroundWidget( intf_thread_t *_p_i )
                  :QWidget( NULL ), p_intf( _p_i )