title: Subtitles of UITableViewCell won't update
body: <p>Today I started to get my apps ready for iOS8.
  I discovered that the subtitles of my UITableCells won't update within <code>viewWillAppear</code>.
  I brought that down to a minimal example:</p>
  
  <p>I've got a static cell TableViewController with 2 cells (style = subtitle)
  One subtitle is empty the other one is set.</p>
  
  <p><img src="https://i.stack.imgur.com/gGjra.png" alt="Interface builder screenschot"></p>
  
  <p>I update the subtitles like this:</p>
  
  <pre><code>- (void) viewWillAppear:(BOOL)animated
  {
    [super viewWillAppear:animated];
    [[self.without detailTextLabel] setText:@"foobar"];
    [[self.with detailTextLabel] setText:@"barfoo"];
  }
  </code></pre>
  
  <p>While everythin works under iOS7 (and 6 and 5), iOS8 won't update the title of the first cell.</p>
  
  <p><img src="https://i.stack.imgur.com/EgR0n.png" alt="screenshot of simulator"></p>
  
  <p>However, when I touch the cell it will update and show the text.</p>
  
  <p>Is this a simulator issue? A bug? Am I doing something wrong?</p>