Collapse children without parent
I found this in the JS console:
```
Uncaught TypeError: e.parentNode is null
collapse_children https://erp-prod.jurassicfruit.net/dist/tryton-sao.min.js:4
collapse_row https://erp-prod.jurassicfruit.net/dist/tryton-sao.min.js:4
toggle_row https://erp-prod.jurassicfruit.net/dist/tryton-sao.min.js:4
e https://erp-prod.jurassicfruit.net/dist/tryton-sao.min.js:4
jQuery 2
```
I do not know how to reproduce but `toggle_row` is called by keypress or click as callback so it could happen when the row was already removed from the parent.
So it will be safer to not always expect a parent node.
issue