title: Rxjava onNext not firing via retrofit observable
body: <p>I have this simple retrofit2 api interface which contains </p>
  
  <pre><code>interface Api {
      @GET(BuildConfig.END_POINT) Observable&lt;Response&gt; fetchData();
  }
  </code></pre>
  
  <p>So everything is fine when I'm doing a fresh request 
  but let say I fire a request and I un-subscribe immediately and then I try to fire new request it returns nothing. </p>
  
  <p>So, in code it looks something like this:</p>
  
  <p>in Activity::onPause I perform un-subscription and in Activity::onResume I fire the request again.</p>
  
  <p>My request looks something like this::</p>
  
  <pre><code>api.fetchData()
      .timeout(30,TimeUnit.SECONDS)
      .doOnNext(new Action1&lt;Response&gt;() {
          @Override public void call(Response response) {
              list = response.getDataForList();
          }
      }).flatMap(new Func1&lt;Response, Observable&lt;List&lt;Object&gt;&gt;&gt;() {
          @Override public Observable&lt;Object&gt;&gt; call(Response response) {
              return Observable.just(list);
          }
      });
  </code></pre>
  
  <p>When I tried debugging it, the call is made but doOnNext() is not called. None of the lifecycle methods are called.</p>
  
  <p>And just for clarification from here I'm just returning the observable which I'm using it somewhere else where I'm observing on main thread and subscribing on IO.</p>