The camel http4 component does not send a body when the http method DELETE is used

Issue

For some reason the camel-http4 component doesn't forward the body when used in conjunction with a DELETE http method. This makes the use of http4 in a proxy configuration for a REST service more or less impossible.

Example proxy route: the body of a delete is not send to the second route:

     <camelContext id="http-delete" trace="true" xmlns="http://camel.apache.org/schema/blueprint">
        <route id="proxy">
            <from id="source" uri="jetty:http://localhost:9999?matchOnUriPrefix=true"/>
            <setHeader headerName="CamelHttpMethod">
                <constant>DELETE</constant>
            </setHeader>
            <setBody>
                <constant>this should be sent to the second route</constant>
            </setBody>
            <to id="destination" uri="http4://localhost:9998?bridgeEndpoint=true&amp;throwExceptionOnFailure=false"/>
        </route>
        <route id="proxy2">
            <from id="source2" uri="jetty:http://localhost:9998?matchOnUriPrefix=true"/>
            <to id="destination2" uri="log:result"/>
        </route>
    </camelContext>