refactor: log error when payload too large

router.go

@@ -707,7 +707,9 @@ func (p *ControllerRegister) ServeHTTP(rw http.ResponseWriter, r *http.Request)
 
 	if r.Method != http.MethodGet && r.Method != http.MethodHead {
 		if BConfig.CopyRequestBody && !context.Input.IsUpload() {
+			// connection will close if the incoming data are larger (RFC 7231, 6.5.11)
 			if r.ContentLength > BConfig.MaxMemory {
+				logs.Error(errors.New("payload too large"))
 				exception("413", context)
 				goto Admin
 			}