Fix typo

Author: Vlad Ghita

security/access_denied_handler.rst

@@ -10,7 +10,7 @@ to disallow access to the user. Symfony will handle this exception and
 generates a response based on the authentication state:
 
 * **If the user is not authenticated** (or authenticated anonymously), an
-  authentication entry point is used to generated a response (typically
+  authentication entry point is used to generate a response (typically
   a redirect to the login page or an *401 Unauthorized* response);
 * **If the user is authenticated, but does not have the required
   permissions**, a *403 Forbidden* response is generated.