[symfony#3089] Removing logout key, since this isn't the logout section

Author: weaverryan

book/security.rst

@@ -411,9 +411,9 @@ submission (i.e. ``/login_check``):
  to this URL.
 
 .. versionadded:: 2.1
- As of Symfony 2.1, you *must* have routes configured for your ``login_path``,
- ``check_path`` ``logout`` keys. These keys can be route names (as shown
- in this example) or URLs that have routes configured for them.
+ As of Symfony 2.1, you *must* have routes configured for your ``login_path``
+ and ``check_path``. These keys can be route names (as shown in this example)
+ or URLs that have routes configured for them.
 
 Notice that the name of the ``login`` route matches the``login_path`` config
 value, as that's where the security system will redirect users that need