fix(multiSelection): catch error if multiselection has no values

Signed-off-by: Florian Steffens <florian.steffens@nextcloud.com>

src/shared/components/ncTable/mixins/columnsTypes/selectionMultiMixin.js

@@ -21,7 +21,7 @@ export default {
 			// values is an array of option-ids as string
 
 			const objects = []
-			values.forEach(id => {
+			values?.forEach(id => {
 				objects.push(this.getOptionObjectForSelectionMulti(parseInt(id), column))
 			})
 			return objects