title: NSTableView: second Column appears when it shouldn't
body: <p>I have an NSTableView with only one column. When I change the Windows size, the TableView sticks to the Windows borders, as it should:
  <a href="https://i.stack.imgur.com/0tfgD.png" rel="nofollow noreferrer">ScreenShot Small</a></p>
  
  <p>However, when I expand the windows frame to much (for example, when using full screen) suddenly a second column appears:
  <a href="https://i.stack.imgur.com/VV9UB.png" rel="nofollow noreferrer">ScreenShot FullScreen</a></p>
  
  <p>I have no idea, why this is happening. I can't expand the first cell manually using this little resize indicator, it seems like the cell inside the tableview just wouldn't be able to grow more...</p>
  
  <p>Here is a picture of the TableViews Attributes Inspector:
  <a href="https://i.stack.imgur.com/RaPr9.png" rel="nofollow noreferrer">ScreenShot AttributeInspector</a></p>
  
  <p>I didn't find any constraints or width settings that would explain this.</p>
  
  <p>I would be really greatful for any kind of help.</p>