title: change throttle parameter dynamically
body: <p>Is it possible to change the throttle parameter (in this case "30") dynamically at runtime? Or do I have to create a new subscription with a new throttle time?</p>
  
  <pre><code>let disposable = Observable.combineLatest(objectA.asObservable().skip(1), 
                                            objectB.asObservable().skip(1))
                             .throttle(30, 
                                       scheduler: ConcurrentDispatchQueueScheduler(qos: .background))
                             .subscribe(onNext: { [unowned self] _ in
                      self.update()
              })
  </code></pre>
  
  <p>My solution would be to dispose of the current subscription and create a new subscription with the new desired throttle time. But is there a better solution?</p>