minor #28347 Fix usage of setUp in tests (fabpot)

This PR was merged into the 2.8 branch.

Discussion
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Fix usage of setUp in tests

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | no
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| License       | MIT

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Commits
-------

62e620843e fixed usage of setUp in tests

src/Symfony/Component/Security/Csrf/Tests/CsrfTokenManagerTest.php

@@ -210,12 +210,12 @@ class CsrfTokenManagerTest extends TestCase
         );
     }
 
-    public function setUp()
+    protected function setUp()
     {
         $_SERVER['HTTPS'] = 'on';
     }
 
-    public function tearDown()
+    protected function tearDown()
     {
         parent::tearDown();