"rows / groups is not iterable" with nested elements

[Bo-Duke]

Using the last version of the lib available on npm, it seems to crash on "nested" schemas.

For example, the "Array/List", "Referencing" or "Recursion" schemas from the Playground don't work, whereas the most simple ones like "Object/Dict" work as intended.

I made a small codesandbox to showcase that : https://codesandbox.io/p/sandbox/condescending-khorana-ddgtyx

The problem seems to come from this line : https://github.com/bhch/react-json-form/blob/8a40fab9f8be6e6cee106243cde794294eaedb36/src/ui.js#L383

I tried using the minified file used in the playground, and it seemed to work : https://github.com/bhch/react-json-form/blob/master/docs/static/js/react-json-form.js