title: viewForHeaderInSection is called for every section but the first UITableView
body: <p>I have a <code>UITableView</code> and a <code>UITableViewController</code> which is the delegate of the table view. I have multiple sections in my <code>UITableView</code>, and I need to set a custom header for the first section. Unfortunately, the method <code>override func tableView(tableView: UITableView!, viewForHeaderInSection section: Int) -&gt; UIView!</code> (swift) is being called for every section but section 0 which is the first section. All of my other <code>UITableView</code> delegate and datasource methods are working correctly and I have no methods that should override this method.</p>