minor #9598 [SecurityBundle] minor simplification in main configuration (shieldo)

This PR was merged into the master branch.

Discussion
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[SecurityBundle] minor simplification in main configuration

As per @stof's suggestion (https://github.com/symfony/symfony/pull/9587#discussion_r7875630).

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
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0d8c34b [SecurityBundle] minor simplification in main configuration

src/Symfony/Bundle/SecurityBundle/DependencyInjection/MainConfiguration.php

@@ -224,6 +224,7 @@ class MainConfiguration implements ConfigurationInterface
                     ->ifTrue(function($v) { return isset($v['csrf_provider']); })
                     ->then(function($v) {
                         $v['csrf_token_generator'] = $v['csrf_provider'];
+                        unset($v['csrf_provider']);
 
                         return $v;
                     })
@@ -232,14 +233,6 @@ class MainConfiguration implements ConfigurationInterface
                     ->ifTrue(function($v) { return isset($v['intention']); })
                     ->then(function($v) {
                         $v['csrf_token_id'] = $v['intention'];
-
-                        return $v;
-                    })
-                ->end()
-                ->beforeNormalization()
-                    ->always()
-                    ->then(function ($v) {
-                        unset($v['csrf_provider']);
                         unset($v['intention']);
 
                         return $v;