title: MassTransit 3 suppress host element in message payload
body: <p>I've recently upgradeed one of our solutions from MassTransit 2 to 3 and since the upgrade, we've noticed that MT 3 is appending an extra host information detail appended to the message payload (detail omitted):</p>
  
  <pre><code>{
      "messageId": "guid",
      "conversationId": "guid",
      "sourceAddress": "rabbitmq://rabbitserver/source",
      "destinationAddress": "rabbitmq://rabbitserver/destination",
      "messageType": [
          ...
      ],
      "message": {
          ...
      },
      "headers": {},
      "host": {
          "machineName": "...",
          "processName": "...",
          "processId": 1234,
          "assembly": "MassTransit",
          "assemblyVersion": "3.1.2.383",
          "frameworkVersion": "...",
          "massTransitVersion": "3.1.2.383",
          "operatingSystemVersion": "..."
      }
  }
  </code></pre>
  
  <p>We'd like to suppress the host information from being added or to rename it as it's causing conflicts in our system.</p>
  
  <p>I've looked at creating middleware as mentioned here: <a href="https://stackoverflow.com/questions/35049641/adding-values-to-header-in-masstransit-rabbitmq">Adding values to header in MassTransit.RabbitMq</a> but can't seem to get access to the data to removed it and after a quick look in the code from github, I can't see any option to not send the host info.  Is there something I'm missing, or is there a way I can remove/rename this data when the message is published?</p>