Update buil_json.html

buil_json.html

@@ -108,7 +108,7 @@ document.addEventListener('DOMContentLoaded', function() {
   document.getElementById('saveToClipboard').addEventListener('click', function() {
     const json = editor.get();
     const autonext = document.getElementById('autonext').checked ? 1 : 0;
-    const jsonString = JSON.stringify({ ...json, autonext });
+    const jsonString = JSON.stringify(json) + (autonext ? ', "autonext":1' : '');
     navigator.clipboard.writeText(jsonString).then(function() {
       alert('JSON saved to clipboard!');
     }, function(err) {