Help Desk Ticket Reference: https://c.na7.visual.force.com/apex/Case_View?id=500A0000003hT0pIAE
project_key: SOA

https://issues.jboss.org/browse/SOA-1962
updated the docs but the code example underneath - Example 12.18. Sample Configuration 
needs to show the example too. that way it wil be clearer to readers.

ie.

<action name="httprouter"  class="org.jboss.soa.esb.actions.routing.http.HttpRouter">
    <property name="endpointUrl"value="http://host:80/blah">
        <http-client-property name="file" value="/ht.props"/>
    </property>
    <property name="method" value="GET"/>
    <property name="responseType" value="STRING"/>
    <property name="headers">
        <header name="blah" value="blahval" ></header>
    </property>
    <property name="MappedHeaderList" value="Connection, Authorization, SOAPAction, Content-Type, Accept, User-Agent, Content-Length, Host">
    </property>
</action>