title: Rebus & RabbitMq always seems to use "RabbitTopics" exchange
body: <p>I am trying to get rebus.rabbitmq (4.4.2.0) to use a specific exchange name to send messages via rabbitmq, but no matter what I do with the configuration, it persistently distributes to an exchange called "RebusTopics", I'm expecting "RebusBus" from the configuration. Am I doing something wrong in the configuration here?</p>
  
  <pre><code>using (var publisher = new BuiltinHandlerActivator())
  {
  
      var publishBus = Configure.With(publisher)
          .Transport(y =&gt; y.UseRabbitMq(rabbitUrl, "_Rebus")
          .ExchangeNames(directExchangeName: "RebusBus"))
          .Start();
  
      publishBus.Advanced.Topics.Publish("Debug", new DebugMessage()).Wait();
  }
  </code></pre>