title: How to Center Text in UITableView.tableHeaderView?
body: <p>I am adding a UILabel to the tableHeaderView but for some reason it is left aligned. </p>
  
  <pre><code>self.messageLabel = [[UILabel alloc] initWithFrame:CGRectZero]; 
  [self.messageLabel setText:@"Nothing to display!"];
  
  [self.tableView setTableHeaderView:self.messageLabel];
  [self.tableView.tableHeaderView setBackgroundColor:[UIColor blueColor]];
  [self.tableView.tableHeaderView setFrame:CGRectMake(320/2, 480/2, 100, 20)];
  [self.messageLabel setCenter:self.tableView.tableHeaderView.center];
  </code></pre>