bug #4757 [Components][ClassLoader] don't show deprecated usage of Yaml::parse() (xabbuh)

This PR was merged into the 2.5 branch.

Discussion
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[Components][ClassLoader] don't show deprecated usage of Yaml::parse()

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.5+
| Fixed tickets |

Commits
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9a620c4 don't show deprecated usage of Yaml::parse()

Author: wouterj

components/class_loader/psr4_class_loader.rst

@@ -55,7 +55,7 @@ first need to configure the ``Psr4ClassLoader``:
     $loader->addPrefix('Symfony\\Component\\Yaml\\', __DIR__.'/lib/Yaml');
     $loader->register();
 
-    $data = Yaml::parse(__DIR__.'/config.yml');
+    $data = Yaml::parse(file_get_contents(__DIR__.'/config.yml'));
 
 First of all, the class loader is loaded manually using a ``require``
 statement, since there is no autoload mechanism yet. With the