show configuration frame

def configure(self, event=None):
        """show configuration frame"""
        if self.win_config is not None:
            try:
                self.win_config.Raise()
            except:
                self.win_config = None

        if self.win_config is None:
            self.win_config = PlotConfigFrame(parent=self,
                                              config=self.conf,
                                              trace_color_callback=self.trace_color_callback)
            self.win_config.Raise()