more defaults, this shouldn't happen but...

freeswitch kazoo.xml should have

  <!-- Hangup -->
     <header name="Hangup-Code" />
     <header name="Hangup-Cause" />
     <header name="variable_bridge_hangup_cause" />
     <header name="variable_hangup_cause" />
     <header name="variable_bridge_hangup_code" />
     <header name="variable_hangup_code" />
     <header name="variable_last_bridge_proto_specific_hangup_cause" />
     <header name="variable_proto_specific_hangup_cause" />
     <header name="variable_last_bridge_proto_specific_hangup_code" />
     <header name="variable_proto_specific_hangup_code" />