title: UITableView - adjustsFontSizeToFitWidth in sectionHeader
body: <p>I've created a custom <code>sectionHeader</code> for my <code>UITableview</code>. </p>
  
  <p>Sometimes I have to fill it with large text, so I added <code>adjustsFontSizeToFitWidth = true</code> which normally works.</p>
  
  <p>In this case the font is not resized when it is to large. Does anyone have an idea what I'm doing wrong?</p>
  
  <pre><code>override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -&gt; UIView? {
      let headerView = UIView()
      headerView.backgroundColor = UIColor.lightGray
  
      let headerLabel = UILabel(frame: CGRect(x: 30, y: 0, width:
          tableView.bounds.size.width, height: tableView.bounds.size.height))
      headerLabel.textColor = UIColor.white
      headerLabel.text = self.tableView(self.tableView, titleForHeaderInSection: section)
      headerLabel.sizeToFit()
      headerLabel.adjustsFontSizeToFitWidth = true
      headerLabel.clipsToBounds=true
      headerLabel.numberOfLines=0
      headerLabel.lineBreakMode = NSLineBreakMode.byTruncatingTail
      headerLabel.minimumScaleFactor = 0.4
      headerView.addSubview(headerLabel)
  
      return headerView
  }
  </code></pre>