minor symfony#25608 [Config] Fix closure CS (issei-m)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes symfony#25608).

Discussion
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[Config] Fix closure CS

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md files -->
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Commits
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d4a428c [Config] Fix closure CS

Author: nicolas-grekas

src/Symfony/Component/Config/Definition/Builder/ExprBuilder.php

@@ -161,7 +161,7 @@ public function thenEmptyArray()
      */
     public function thenInvalid($message)
     {
-        $this->thenPart = function ($v) use ($message) {throw new \InvalidArgumentException(sprintf($message, json_encode($v))); };
+        $this->thenPart = function ($v) use ($message) { throw new \InvalidArgumentException(sprintf($message, json_encode($v))); };
 
         return $this;
     }