new cs rule: single_line_empty_body

Rule is added to the last version of php-cs-fixer

src/Bundle/ChillPersonBundle/Serializer/Normalizer/PersonJsonNormalizerInterface.php

@@ -19,6 +19,4 @@ use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
  */
 interface PersonJsonNormalizerInterface extends
     DenormalizerInterface,
-    NormalizerInterface
-{
-}
+    NormalizerInterface {}