add validation for onClose

src/client/js/components/TopOfTableContents.jsx

@@ -25,6 +25,9 @@ const TopOfTableContents = (props) => {
   }
 
   function closePageAccessoriesModal() {
+    if (props.onClose == null) {
+      return;
+    }
     setIsPageAccessoriesModalShown(false);
   }
 
@@ -77,6 +80,7 @@ const TopOfTableContentsWrapper = withUnstatedContainers(TopOfTableContents, [Pa
 
 TopOfTableContents.propTypes = {
   pageContainer: PropTypes.instanceOf(PageContainer).isRequired,
+  onClose: PropTypes.func,
 };
 
 export default withTranslation()(TopOfTableContentsWrapper);