minor #13829 Update access_control.rst (atailouloute)

This PR was merged into the 3.4 branch.

Discussion
----------

Update access_control.rst

Small fix

Commits
-------

2c19997 Update access_control.rst

Author: javiereguiluz

security/access_control.rst

@@ -320,7 +320,7 @@ key:
                     // the 'role' and 'allow-if' options work like an OR expression, so
                     // access is granted if the expression is TRUE or the user has ROLE_ADMIN
                     'roles' => 'ROLE_ADMIN',
-                    'allow_if' => '"127.0.0.1" == request.getClientIp() or request.headers.has('X-Secure-Access')',
+                    'allow_if' => '"127.0.0.1" == request.getClientIp() or request.headers.has("X-Secure-Access")',
                 ],
             ],