minor #16844 [Security] Fix second Twig path reference to be consistent with the first reference (yobrx)

This PR was merged into the 5.4 branch.

Discussion
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[Security] Fix second Twig path reference to be consistent with the first reference

I found an inconsistency in the Security documentation :

![image](https://user-images.githubusercontent.com/292402/171823645-2556f153-2002-4afc-adfe-f41e2e3919b7.png)

![image](https://user-images.githubusercontent.com/292402/171823749-83977ea5-fe25-47d3-8435-410ee6b34609.png)

This PR fix that.

Commits
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03e8588 Fix second twig path reference to be consistent with the first reference on security documentation

Author: javiereguiluz

security.rst

@@ -939,7 +939,7 @@ be ``authenticate``:
 
 .. code-block:: html+twig
 
-    {# templates/security/login.html.twig #}
+    {# templates/login/index.html.twig #}
 
     {# ... #}
     <form action="{{ path('login') }}" method="post">