minor #10925 MakerBundle v1.11.13 uses urlGenerator instead of Router (romaricdrigon)

This PR was submitted for the 4.2 branch but it was merged into the 4.1 branch instead (closes #10925).

Discussion
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MakerBundle v1.11.13 uses urlGenerator instead of Router

Hello,

Since version 1.11.3 and PR [#349](symfony/maker-bundle#349) MakerBundle uses `UrlGeneratorInterface` instead of `RouterInterface` when generating a new Guard for a login form, and the corresponding property changed. Hence the documentation code snippet is misleading.

I'm not totally sure of which branch to PR on; being a change from latest version of MakerBundle, I think this is especially important for new projects, so using the latest Symfony version.

Commits
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f00344a MakerBundle uses urlGenerator instead of Router

Author: javiereguiluz

security/form_login_setup.rst

@@ -295,7 +295,7 @@ be redirected after success:
 
     -     throw new \Exception('TODO: provide a valid redirect inside '.__FILE__);
     +     // redirect to some "app_homepage" route - of wherever you want
-    +     return new RedirectResponse($this->router->generate('app_homepage'));
+    +     return new RedirectResponse($this->urlGenerator->generate('app_homepage'));
     }
 
 Unless you have any other TODOs in that file, that's it! If you're loading users