minor #5242 Update load_balancer_reverse_proxy.rst (urg)

This PR was submitted for the 2.6 branch but it was merged into the 2.3 branch instead (closes #5242).

Discussion
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Update load_balancer_reverse_proxy.rst

Remind that the trusted_proxies setting needs to be removed or the setTrustedProxies method call will be overwritten.

Commits
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da65156 Adjust line wrapping
4d8c89d Add formatting for file and method names
037eda8 Update load_balancer_reverse_proxy.rst

Author: weaverryan

cookbook/request/load_balancer_reverse_proxy.rst

@@ -83,6 +83,9 @@ In this case, you'll need to - *very carefully* - trust *all* proxies.
        $response = $kernel->handle($request);
        // ...
 
+#. Ensure that the trusted_proxies setting in your ``app/config/config.yml`` 
+   is not set or it will overwrite the ``setTrustedProxies`` call above.
+
 That's it! It's critical that you prevent traffic from all non-trusted sources.
 If you allow outside traffic, they could "spoof" their true IP address and
 other information.