bug #9910 fixed missing use statements (fabpot)

This PR was merged into the 2.4 branch.

Discussion
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fixed missing use statements

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| 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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50a6d70 fixed missing use statements

Author: fabpot

DependencyInjection/SecurityExtension.php

@@ -682,7 +682,7 @@ private function getExpressionLanguage()
     {
         if (null === $this->expressionLanguage) {
             if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
-                throw new RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
+                throw new \RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
             }
             $this->expressionLanguage = new ExpressionLanguage();
         }