fix Middleware trait link
@@ -15,7 +15,7 @@ Typically, middleware is involved in the following actions:
Middleware is registered for each application and executed in same order as
registration. In general, a *middleware* is a type that implements the
-[*Middleware trait*](../../actix-web/actix_web/middlewares/trait.Middleware.html).
+[*Middleware trait*](../../actix-web/actix_web/middleware/trait.Middleware.html).
Each method in this trait has a default implementation. Each method can return
a result immediately or a *future* object.
