title: Configuration path "security.access_control" cannot be overwritten
body: <p>I'm busy trying to configurate Fouserbundle on Symfony 2.6.9. But doesn't work, i got this message:</p>
  
  <p><strong>ForbiddenOverwriteException in BaseNode.php line 223: Configuration path "security.access_control" cannot be overwritten. You have to define all options for this path, and any of its sub-paths in one configuration section.</strong></p>
  
  <p>(i did configurate, appkernel, config,composer)</p>
  
  <p><strong>user.php</strong></p>
  
  <pre><code>&lt;?php
  
  namespace FLY\UserBundle\Entity;
  
  use FOS\UserBundle\Model\User as BaseUser;
  use Doctrine\ORM\Mapping as ORM;
  
  /**
   * @ORM\Entity
   * @ORM\Table(name="FLY_user")
   */
  class User extends BaseUser
  {
      /**
       * @ORM\Id
       * @ORM\Column(type="integer")
       * @ORM\GeneratedValue(strategy="AUTO")
       */
      protected $id;
  
      public function __construct()
      {
          parent::__construct();
          // your own logic
      }
  }
  </code></pre>
  
  <p><strong>app/Resources/config/security.yml</strong></p>
  
  <pre><code>imports:
  - { resource: "@FLYUserBundle/Resources/config/security.yml" }
  
  
  security:
      access_control:
          - { path: ^/login$, role: IS_AUTHENTICATED_ANONYMOUSLY }
          - { path: ^/register, role: IS_AUTHENTICATED_ANONYMOUSLY }
          - { path: ^/resetting, role: IS_AUTHENTICATED_ANONYMOUSLY }
          - { path: ^/admin/, role: ROLE_ADMIN }
  
      role_hierarchy:
          ROLE_ADMIN:       ROLE_USER
          ROLE_SUPER_ADMIN: ROLE_ADMIN
  </code></pre>
  
  <p><strong>UserBundle/Resources/config/security.yml</strong></p>
  
  <pre><code>security:
  encoders:
      FOS\UserBundle\Model\UserInterface: sha512
  
  providers:
          fos_userbundle:
              id: fos_user.user_manager
  
  firewalls:
  
      main:
                  pattern: ^/
                  form_login:
                      provider: fos_userbundle
                      csrf_provider: form.csrf_provider
                  logout:       true
                  anonymous:    true
      dev:
          pattern:  ^/(_(profiler|wdt)|css|images|js)/
          security: false
  
      login:
          pattern:  ^/demo/secured/login$
          security: false
  
      secured_area:
          pattern:    ^/demo/secured/
          form_login:
              check_path: /demo/secured/login_check
              login_path: /demo/secured/login
          logout:
              path:   /demo/secured/logout
              target: /demo/
          #anonymous: ~
          #http_basic:
          #    realm: "Secured Demo Area"
  </code></pre>
  
  <p><strong>app/Resources/config/routing.yml</strong></p>
  
  <pre><code>FLY_Platform:
  resource: "@FLYPlatformBundle/Resources/config/routing.yml"
  prefix:   /
  
  
  mremi_contact_form:
      resource: "@MremiContactBundle/Resources/config/routing.xml"
  
  genemu_base64:
          resource: "@GenemuFormBundle/Resources/config/routing/base64.xml"
  
  _user_bundle:
      resource: "@UserBundle/Resources/config/routing.yml"
  </code></pre>
  
  <p><strong>UserBundle/Resources/config/routing.yml</strong></p>
  
  <pre><code>fos_user_security:
  resource: "@FOSUserBundle/Resources/config/routing/security.xml"
  
  
  fos_user_profile:
      resource: "@FOSUserBundle/Resources/config/routing/profile.xml"
      prefix: /profile
  
  fos_user_register:
      resource: "@FOSUserBundle/Resources/config/routing/registration.xml"
      prefix: /register
  
  fos_user_resetting:
      resource: "@FOSUserBundle/Resources/config/routing/resetting.xml"
      prefix: /resetting
  
  fos_user_change_password:
      resource: "@FOSUserBundle/Resources/config/routing/change_password.xml"
      prefix: /profile
  </code></pre>
  
  <p>Thank you </p>