minor symfony#17173 [DependencyInjection] fixes typo in triggered deprecation notice. (hhamon)

This PR was merged into the 2.7 branch.

Discussion
----------

[DependencyInjection] fixes typo in triggered deprecation notice.

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

Commits
-------

ba7213c [DependencyInjection] fixes typo in triggered deprecation notice.

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/SimpleXMLElement.php

@@ -11,7 +11,7 @@
 
 namespace Symfony\Component\DependencyInjection;
 
-@trigger_error('The '.__NAMESPACE__.'\SimpleXMLElement method is deprecated since version 2.5 and will be removed in 3.0.', E_USER_DEPRECATED);
+@trigger_error('The '.__NAMESPACE__.'\SimpleXMLElement class is deprecated since version 2.5 and will be removed in 3.0.', E_USER_DEPRECATED);
 
 use Symfony\Component\Config\Util\XmlUtils;
 use Symfony\Component\ExpressionLanguage\Expression;