fix(files_versions): "undefined restored" on restore

Signed-off-by: Alejo <xlejo@protonmail.com>

Author: xlejo

apps/files_versions/src/views/VersionTab.vue

@@ -199,7 +199,7 @@ export default {
 
 			try {
 				await restoreVersion(version)
-				if (version.label !== '') {
+				if (version.label) {
 					showSuccess(t('files_versions', `${version.label} restored`))
 				} else if (version.mtime === this.initialVersionMtime) {
 					showSuccess(t('files_versions', 'Initial version restored'))