title: matplotlib figure parameters don't appears
body: <p>Here is my issue: I have an embedded matplotlib figure in a Qt5 application. When I press the button "edit axis, curve and image parameter", I select my concerned subplot, but only the tab "axis" options appears. it is missing tabs for "curve" and "image". </p>
  
  <p>actual picture</p>
  
  <p><img src="https://i.stack.imgur.com/6pdqu.png" alt=""></p>
  
  <p>whereas I should have had something like this:</p>
  
  <p>targeted picture</p>
  
  <p><img src="https://i.stack.imgur.com/Rj2OU.png" alt=""></p>
  
  <p>If anyone knows why...</p>