title: UILabel in UITableViewCell in .xib file ignores Dark Mode
body: <p>I have my custom <code>UITableViewCells</code> in <code>.xib</code> files. Since Xcode 11 Beta 5 (also tested with Beta 6) my <code>UILabels</code> ignore the Dark Mode and the text is always black. I have set the <code>UILabel</code> text color to Default (Label Color) so this should change automatically. Does anyone have an ideas what's wrong?</p>
  
  <p>Here is a screenshot: The first cell is a basic cell, the second one is a custom cell in a <code>.xib</code> file.</p>
  
  <p><a href="https://i.stack.imgur.com/5MLR4.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/5MLR4.jpg" alt="enter image description here"></a></p>