[Yaml] Recommend using quotes instead of PARSE_KEYS_AS_STRINGS

Author: GuilhemN

Loader/YamlFileLoader.php

@@ -15,7 +15,6 @@
 use Symfony\Component\Translation\Exception\LogicException;
 use Symfony\Component\Yaml\Parser as YamlParser;
 use Symfony\Component\Yaml\Exception\ParseException;
-use Symfony\Component\Yaml\Yaml;
 
 /**
  * YamlFileLoader loads translations from Yaml files.
@@ -40,7 +39,7 @@ protected function loadResource($resource)
         }
 
         try {
-            $messages = $this->yamlParser->parse(file_get_contents($resource), Yaml::PARSE_KEYS_AS_STRINGS);
+            $messages = $this->yamlParser->parse(file_get_contents($resource));
         } catch (ParseException $e) {
             throw new InvalidResourceException(sprintf('Error parsing YAML, invalid file "%s"', $resource), 0, $e);
         }