[fix] resource_private.opa: remove deprecated warning

stdlib/core/web/resource/resource_private.opa

@@ -914,7 +914,7 @@ export_resource(external_css_files: list(string),
           uri        = get_request_uri(req)
           num_page = match thread_context().key with
             | ~{client}-> do %%BslPingRegister.client_start%%(client) client.page
-            | _ -> result = Random.int(max_int)
+            | _ -> result = Random.int(Limits.max_int)
                    do Log.warning("Resource export",
                       "This page is exported from a context that doesn't have a valid client thread context. Replacing by random value {result}")
                    result