return method not allowed error

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

handler.go

@@ -117,7 +117,7 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			handler = hdlr
 			break
 		} else if err == rhttp.ErrMethodNotAllowed && !h.registerRPC {
-			h.errorHandler(ctx, nil, w, r, fmt.Errorf("not matching route found"), http.StatusNotFound)
+			h.errorHandler(ctx, nil, w, r, fmt.Errorf("not matching route found"), http.StatusMethodNotAllowed)
 			return
 		}
 	}