title: Styling of QComboBox: How to remove shadow on listview?
body: <p>I am trying to make Qt application restyling using qss (qt stylesheet) and QProxyStyle. And can't find a way to remove shadow of listview.
  Seems that it is not possible to do with the style, but i beleive it should be possible with the QProxyStyle.</p>
  
  <p><img src="https://i.stack.imgur.com/Fk01w.png" alt="qcombobox shadow"></p>