[TwigBundle] fixed configuration to avoid key normalizations for paths and globals (closes #5998)

src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php

@@ -76,6 +76,7 @@ class Configuration implements ConfigurationInterface
             ->fixXmlConfig('global')
             ->children()
                 ->arrayNode('globals')
+                    ->keepKeys()
                     ->useAttributeAsKey('key')
                     ->example(array('foo' => '"@bar"', 'pi' => 3.14))
                     ->prototype('array')
@@ -126,6 +127,7 @@ class Configuration implements ConfigurationInterface
                 ->scalarNode('auto_reload')->end()
                 ->scalarNode('optimizations')->end()
                 ->arrayNode('paths')
+                    ->keepKeys()
                     ->beforeNormalization()
                         ->always()
                         ->then(function ($paths) {