Revert "bug #19114 [HttpKernel] Dont close the reponse stream in debug (nicolas-grekas)"

This reverts commit a0cdcb0, reversing
changes made to 9c8a3e9.

Author: fabpot

Kernel.php

@@ -149,14 +149,6 @@ public function terminate(Request $request, Response $response)
         }
 
         if ($this->getHttpKernel() instanceof TerminableInterface) {
-            if (!$this->debug) {
-                if (function_exists('fastcgi_finish_request')) {
-                    fastcgi_finish_request();
-                } elseif ('cli' !== PHP_SAPI) {
-                    Response::closeOutputBuffers(0, true);
-                }
-            }
-
             $this->getHttpKernel()->terminate($request, $response);
         }
     }