no need to check SUPPORTS_WEBDAV_LOCKS manually. wl_isLocked() is defined and defaults to false if SUPPORTS_WEBDAV_LOCKS is false

git-svn-id: https://svn.erp5.org/repos/public/erp5/sandbox/portal_types@29484 20353a03-c40f-0410-a6d1-a30d3c3de9de