title: WxPython StaticBitmap not clearing
body: <ul>
  <li>I want to load a StaticBitmap in a Scrolledcanvas</li>
  <li>First time is OK.</li>
  <li>Then I want to upload another one in place of the existing one.</li>
  <li>But I do not manage to clear the ScrolledCanvas : 
  
  <ul>
  <li>both image appears</li>
  </ul></li>
  </ul>
  
  <pre><code>class FAI(wx.Frame):
   .... init stuff ....
  
          self.viewer = wx.ScrolledCanvas(self)
          self.viewer.SetScrollbars(1, 1, 500, 500)
          self.CreateStatusBar()
  
          self.inside_view = wx.BoxSizer()
          self.viewer.SetSizer(self.inside_view)
  
      def im_load(self, event):  # wxGlade: MyFrame.&lt;event_handler&gt;
          dlg = wx.FileDialog(None)
          if dlg.ShowModal() == wx.ID_OK:
              path = dlg.GetPath()
              print("%s" % dlg.GetPath())
          image = wx.StaticBitmap(
              self.viewer, wx.ID_ANY, wx.Bitmap(path, wx.BITMAP_TYPE_ANY)
          )
          self.inside_view.Add(image)
          self.Refresh()
          dlg.Destroy()
  
  class MyApp(wx.App):
  ......
  </code></pre>