WithNotFoundHandler should be supported to decide whether to use the built-in log middleware according to the configuration

[weitrue]

func (ng *engine) bindFeaturedRoutes(router httpx.Router, fr featuredRoutes, metrics *stat.Metrics) error {
	verifier, err := ng.signatureVerifier(fr.signature)
	if err != nil {
		return err
	}

	for _, route := range fr.routes {
		if err := ng.bindRoute(fr, router, metrics, route, verifier); err != nil {
			return err
		}
	}

	return nil
}


func (ng *engine) notFoundHandler(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		chn := chain.New(
			handler.TraceHandler(ng.conf.Name,
				"",
				handler.WithTraceIgnorePaths(ng.conf.TraceIgnorePaths)),
			ng.getLogHandler(),
		)

		var h http.Handler
		if next != nil {
			h = chn.Then(next)
		} else {
			h = chn.Then(http.NotFoundHandler())
		}

		cw := response.NewHeaderOnceResponseWriter(w)
		h.ServeHTTP(cw, r)
		cw.WriteHeader(http.StatusNotFound)
	})
}

为什么bindFeaturedRoutes从v1.4.4开始支持根据配置决定是否启用内置的log middleware,但是notFoundHandler 到v1.5.2版本还不支持呢？