[Security]: Removing duplicate sentence

Page: https://symfony.com/doc/6.4/security.html#the-firewall

Namely:
> Here, all real URLs are handled by the ``main`` firewall (no ``pattern`` key means
it matches *all* URLs).

Author: ThomasLandauer

security.rst

@@ -575,7 +575,8 @@ Only one firewall is active on each request: Symfony uses the ``pattern`` key
 to find the first match (you can also
 :doc:`match by host or other things </security/firewall_restriction>`).
 Here, all real URLs are handled by the ``main`` firewall (no ``pattern`` key means
-it matches *all* URLs).
+it matches *all* URLs). A firewall can have many modes of authentication,
+in other words, it enables many ways to ask the question "Who are you?".
 
 The ``dev`` firewall is really a fake firewall: it makes sure that you
 don't accidentally block Symfony's dev tools - which live under URLs like
@@ -630,10 +631,6 @@ don't accidentally block Symfony's dev tools - which live under URLs like
 
         The feature to use an array of regex was introduced in Symfony 6.4.
 
-All *real* URLs are handled by the ``main`` firewall (no ``pattern`` key means
-it matches *all* URLs). A firewall can have many modes of authentication,
-in other words, it enables many ways to ask the question "Who are you?".
-
 Often, the user is unknown (i.e. not logged in) when they first visit your
 website. If you visit your homepage right now, you *will* have access and
 you'll see that you're visiting a page behind the firewall in the toolbar: