title: Pycharm : not displaying files on the left
body: <p>I used to have my files on the pycharm box on the left of my window, like that : 
  <a href="https://i.stack.imgur.com/5dKVU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5dKVU.png" alt="enter image description here"></a>
   but now Pycharm displays it under the list of directory : </p>
  
  <p><a href="https://i.stack.imgur.com/VyXNP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VyXNP.png" alt="enter image description here"></a></p>
  
  <p>I can't change of directory on the left part of the window : I have to use the horizontally-stacked list of folders, which is really annoying. Which switch in the conf of Pycharm do I have to check to have the normal behaviour back ? </p>