Fix typo

Author: edpoulain

security/login_link.rst

@@ -664,7 +664,7 @@ user create this POST request (e.g. by clicking a button)::
         <h2>Hi! You are about to login to ...</h2>
 
         <!-- for instance, use a form with hidden fields to
-             create the POST request --->
+             create the POST request -->
         <form action="{{ path('login_check') }}" method="POST">
             <input type="hidden" name="expires" value="{{ expires }}">
             <input type="hidden" name="user" value="{{ user }}">