Removed dead code and various cleaning

Author: saro0h

Authentication/Provider/PreAuthenticatedAuthenticationProvider.php

@@ -59,11 +59,7 @@ public function authenticate(TokenInterface $token)
          if (!$user = $token->getUser()) {
              throw new BadCredentialsException('No pre-authenticated principal found in request.');
          }
-/*
-        if (null === $token->getCredentials()) {
-            throw new BadCredentialsException('No pre-authenticated credentials found in request.');
-        }
-*/
+
         $user = $this->userProvider->loadUserByUsername($user);
 
          $this->userChecker->checkPostAuth($user);