Remove extra session_start()

Prior to this change, the hasSession() would already trigger a session_start from within Symfony Framework. The session_start left in there was not needed and confusing.
This change leaves session handling to the framework and does not try to start the session again manually.

Author: johanib

library/EngineBlock/ApplicationSingleton.php

@@ -238,7 +238,6 @@ public function reportError(Throwable $exception, $messageSuffix = '')
         // Store some valuable debug info in session so it can be displayed on feedback pages
         if($this->hasSession()) {
             // In CLI context, the session is not available
-            @session_start();
             $this->getSession()->set('feedbackInfo', $this->collectFeedbackInfo($exception));
         }