public void respond(JRTServerConfigRequest request) {
        log.log(FINEST, () -> "Trace when responding to " + request + ":\n" + request.getRequestTrace().toString());
        request.getRequest().returnRequest();
    }
Checks all delayed responses for config changes and waits until all has been answered.
This method should be called when config is activated in the server.
configserver/src/main/java/com/yahoo/vespa/config/server/rpc/RpcServer.java