remove nonexisting

Author: themsaid

src/Illuminate/Foundation/Application.php

@@ -1146,7 +1146,6 @@ public function flush()
         parent::flush();
 
         $this->buildStack = [];
-        $this->middlewares = [];
         $this->loadedProviders = [];
         $this->bootedCallbacks = [];
         $this->bootingCallbacks = [];