title: Apache Camel CxfRsEndpoint performInvocation setting triggers invocation twice
body: <p>I have a minimal camel route with a cxf endpoint (in a RouteBuilder#configure method):</p>
  
  <pre><code>CxfRsComponent cxfComponent = new CxfRsComponent(context);
  CxfRsEndpoint serviceEndpoint = new CxfRsEndpoint("http:/localhost/rest", cxfComponent);
  serviceEndpoint.addResourceClass(PersonService.class);
  serviceEndpoint.setPerformInvocation(true);
  
  from(serviceEndpoint).log("this is irrelevant");
  </code></pre>
  
  <p>The issue is that the methods of the resource class are called twice:</p>
  
  <p>Let's say there is a "PersonService#post" method:</p>
  
  <pre><code>public Person post(Person p){
      p.setId(p.getId() + "_PersonService#post");
      return p;
  }
  </code></pre>
  
  <p>It gets invoced twice: breakpoints get hit twice, response for payload</p>
  
  <pre><code>{
      "id" : "id_from_client"
  }
  </code></pre>
  
  <p>is</p>
  
  <pre><code>{
    "id": "id_from_client_PersonService#post_PersonService#post"
  }
  </code></pre>
  
  <p>Is this expected behaviour? If yes, is there a setting to only execute the method once? This seems like a bug to me.</p>
  
  <p>Camel version is 2.16.2 (maven: org.apache.camel:camel-cxf-transport:2.16.2)
  CXF version is 3.1.4 (org.apache.cxf:cxf-rt-transports-http-jetty:3.1.4)</p>