title: UITableView heightForHeaderInSection not working
body: <p>I have a simple UITableView (<a href="http://cl.ly/WGMA" rel="noreferrer">sample project here</a>) but the section headers do not respect the height I'm setting in the <code>heightForHeaderInSection</code></p>
  
  <pre><code>- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
  {
      return 40;
  } 
  </code></pre>
  
  <p>The table view looks like this. The 1 section header has a correct height but not the other ones.</p>
  
  <p><img src="https://i.stack.imgur.com/IAg5A.png" alt="enter image description here"></p>
  
  <p>When I inspect the view with the Reveal app, it seems that there is a kind of footer after the last cell in the section.</p>
  
  <p><img src="https://i.stack.imgur.com/n68a8.png" alt="enter image description here"></p>
  
  <p>What am I doing wrong?</p>