fix default field definition handling
fix default field definition handling

tackerm/SonataDoctrinePhpcrAdminBundle,tackerm/SonataDoctrinePhpcrAdminBundle,sonata-project/SonataDoctrinePhpcrAdminBundle,sonata-project/SonataDoctrinePhpcrAdminBundle,tackerm/SonataDoctrinePhpcrAdminBundle,tackerm/SonataDoctrinePhpcrAdminBundle,sonata-project/SonataDoctrinePhpcrAdminBundle