title: RxSwift Subscribe onNext not called after bind
body: <p>I am using RxSwift 4.0 and build tableView content using <code>DTTableViewManager</code></p>
  
  <p>in Presenter, I have model variable</p>
  
  <p><strong>1</strong></p>
  
  <pre><code>lazy var mostRecent: TableTitleHeaderContainer = {
      let container = TableTitleHeaderContainer(isHidden: true, title: "Title 1")
      return container
  }()
  
  lazy var lastRecent: TableTitleHeaderContainer = {
      let container = TableTitleHeaderContainer(isHidden: false, title: "Title 2")
      return container
  }()
  </code></pre>
  
  <p>code of model</p>
  
  <p><strong>2</strong></p>
  
  <pre><code>class TableTitleHeaderContainer {
      var subject: PublishSubject&lt;Void&gt; = PublishSubject&lt;Void&gt;()
      var isHidden: Bool
      var title: String
      var disposeBag = DisposeBag()
      init(isHidden: Bool, title: String) {
          self.isHidden = false
          self.title = title
      }
  }
  </code></pre>
  
  <p>and view configuration with model </p>
  
  <p><strong>3</strong></p>
  
  <pre><code>extension TableTitleHeaderView: ModelTransfer {
      func update(with model: TableTitleHeaderContainer) {
          clearButton.isHidden = model.isHidden
          clearButton.rx.tap
              .bind(to: model.subject).disposed(by: disposeBag)
          titleLabel.text = model.title
      }
  }
  </code></pre>
  
  <p>And I want to listen tap on button in Presenter</p>
  
  <p><strong>4</strong></p>
  
  <pre><code>mostRecent.subject.asObserver().subscribe(onNext: { [weak self] (_) in
      print("Clear mostRecent")
  }).disposed(by: disposeBag)
  
  lastRecent().subject.asObserver().subscribe(onNext: { [weak self] (_) in
      print("Clear lastRecent")
  }).disposed(by: disposeBag)
  </code></pre>
  
  <p>But after configure view with model subscribe in Presenter does not call?
  What is the trouble?</p>