Do not clone the initial request so that it is replaced correctly.

Cloning the initial request resulted in the cloned request being replaced once an internal
request had been dispatched. This proved troublesome for middlewares that altered the
initial request as the cloned request then replaced the initial request after an
internal request was dispatched.

Reference issue dingo#894.

src/Dispatcher.php

@@ -183,13 +183,13 @@ public function __construct(Container $container, Filesystem $files, Router $rou
     }
 
     /**
-     * Setup the request stack by cloning the initial request.
+     * Setup the request stack by grabbing the initial request.
      *
      * @return void
      */
     protected function setupRequestStack()
     {
-        $this->requestStack[] = clone $this->container['request'];
+        $this->requestStack[] = $this->container['request'];
     }
 
     /**