title: why added blank space between searchBar and tableview?
body: <p>I have a tableview controller. I added searchBar. But when i click on searchBar, i have a blank space between searchBar and TableView? Why? And how it fix?
  In down i add screenshot and listing of code tableViewController. Thanks for help.</p>
  
  <p><a href="https://i.stack.imgur.com/Puz6S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Puz6S.png" alt="After click on searchBar"></a></p>
  
  <p><a href="https://i.stack.imgur.com/eUZvy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eUZvy.png" alt="Click on searchBar"></a></p>
  
  <p>!!!!!! - LISTING TableViewController - !!!!!!</p>
  
  <pre><code>class AlfavitController: UITableViewController, UISearchResultsUpdating {
  
  var searchController : UISearchController!
  var resultController = UITableViewController()
  
  override func viewDidLoad() {
      super.viewDidLoad()
      self.downloadData(param: Manager.id)
  
      tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
  
      self.searchController = UISearchController(searchResultsController: self.resultController)
      self.tableView.tableHeaderView = self.searchController.searchBar
      self.searchController.searchResultsUpdater = self
      self.resultController.tableView.dataSource = self
      self.resultController.tableView.delegate = self
      definesPresentationContext = true
   }
  
  func updateSearchResults(for searchController: UISearchController) {
      self.arFiltLet = self.arWords.filter{(lett : String) -&gt; Bool in
          if lett.lowercased().contains(self.searchController.searchBar.text!.lowercased()){
              return true
          }else{
              return false
          }
      }
      self.resultController.tableView.reloadData()
  }
  
  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -&gt; Int {
      if tableView == self.tableView {
          return self.arWords.count
      }else{
          return self.arFiltLet.count
      }
  }
  
  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -&gt; UITableViewCell {
      let cell = self.tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
      if tableView == self.tableView{
          cell.textLabel?.text = self.arWords[indexPath.row]
      }else{
          cell.textLabel?.text = self.arFiltLet[indexPath.row]
      }
      return cell
  }
  </code></pre>