Fix account dropdown not opening due to regression from #12377 (#12430)

app/javascript/mastodon/containers/dropdown_menu_container.js

@@ -14,7 +14,9 @@ const mapStateToProps = state => ({
 
 const mapDispatchToProps = (dispatch, { status, items }) => ({
   onOpen(id, onItemClick, dropdownPlacement, keyboard) {
+    if (status) {
       dispatch(fetchRelationships([status.getIn(['account', 'id'])]));
+    }
 
     dispatch(isUserTouching() ? openModal('ACTIONS', {
       status,