For the class "PrintoutWx" in backend_wx.py, because it doesn't update the API
change from matplotlib 0.98.3. All of "print" and "print preview" doesn't
work correctly on new version(matplotlib 0.98.3.)
if we change the line in 2109 "self.canvas.figure.dpi.set(fig_dpi)"
Then it works.
Would you please change that.