fix: change to url error

frontend/appflowy_tauri/src/appflowy_app/components/board/BoardUrlCell.tsx

@@ -17,8 +17,8 @@ export const BoardUrlCell = ({
 
   return (
     <>
-      <a className={'text-main-accent hover:underline'} href={(data as URLCellDataPB).url || ''} target={'_blank'}>
-        {(data as URLCellDataPB).content || ''}
+      <a className={'text-main-accent hover:underline'} href={(data as URLCellDataPB)?.url || ''} target={'_blank'}>
+        {(data as URLCellDataPB)?.content || ''}
       </a>
     </>
   );