handler/meter: add HTTPHandlerFunc method

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

handler/meter/meter.go

@@ -99,6 +99,8 @@ func (h *Handler) HTTPHandlerFunc(w http.ResponseWriter, r *http.Request) {
 		defer gz.Close()
 
 		wr = gz
+	} else {
+		wr = w
 	}
 
 	if err := h.Options.Meter.Write(w, h.Options.MeterOptions...); err != nil {