fix: do not inject iframes on chrome's error pages

[shadowusr]

What's done?

Minimal case for this issue:

1. Open any unexisting URL, for example: https://asdf-asdf-non-exist.ing/
2. Execute the following code in devtools js console:

   const iframe = document.createElement("iframe");
   document.body.appendChild(iframe);
   

3. Watch the tab crash

This fix prevents creating iframes on chrome's error pages to avoid this crash.