minor symfony#25680 [FrameworkBundle] Fix recommended composer command (add vendor) (Tomas Kmieliauskas)

This PR was submitted for the master branch but it was merged into the 3.4 branch instead (closes symfony#25680).

Discussion
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[FrameworkBundle] Fix recommended composer command (add vendor)

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

Since running composer commands is time heavy, having a wrong one recommended to you just burns your time.

Commits
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f6d38b3 [FrameworkBundle] Fix recommended composer command (add vendor)

Author: fabpot

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -1418,7 +1418,7 @@ private function registerSecurityCsrfConfiguration(array $config, ContainerBuild
         }
 
         if (!class_exists('Symfony\Component\Security\Csrf\CsrfToken')) {
-            throw new LogicException('CSRF support cannot be enabled as the Security CSRF component is not installed. Try running "composer require security-csrf".');
+            throw new LogicException('CSRF support cannot be enabled as the Security CSRF component is not installed. Try running "composer require symfony/security-csrf".');
         }
 
         if (!$this->sessionConfigEnabled) {