middleware

- fix X-Instance-ID

middleware/instance.go

@@ -23,8 +23,7 @@ func InstanceId() echo.MiddlewareFunc {
 
 			value := context.WithValue(c.Request().Context(), keyInstanceId, id)
 			c.SetRequest(c.Request().WithContext(value))
-
-			return nil
+			return next(c)
 		}
 	}
 }