allow reload ffdec when no swf is opened

src/com/jpexs/decompiler/flash/gui/MainFrameClassic.java

@@ -112,12 +112,6 @@ public final class MainFrameClassic extends AppFrame implements MainFrame {
         View.centerScreen(this);
     }
 
-    @Override
-    public void setVisible(boolean b) {
-        super.setVisible(b);
-        panel.setVisible(b);
-    }
-
     @Override
     public MainPanel getPanel() {
         return panel;