Merge pull request #9093 from owncloud/remove_unused_code

apps/files_encryption/hooks/hooks.php

apps/files_encryption/js/settings-admin.js

apps/files_encryption/lib/keymanager.php

apps/files_encryption/tests/util.php

apps/files_encryption/tests/webdav.php

apps/files_trashbin/lib/trashbin.php

apps/files_versions/lib/versions.php