Avoid app crashing when code (data) is undefined (#681)

* fix: code field ui errors when data is undefined

src/admin/components/views/collections/List/Cell/field-types/Code/index.tsx

@@ -3,7 +3,10 @@ import React from 'react';
 import './index.scss';
 
 const CodeCell = ({ data }) => {
-  const textToShow = data.length > 100 ? `${data.substr(0, 100)}\u2026` : data;
+  let textToShow = '';
+
+  if (data) textToShow = data.length > 100 ? `${data.substr(0, 100)}\u2026` : data;
+
   return (
     <code className="code-cell">
       <span>{textToShow}</span>