Let's assume an editable grouped list view with a <groupby>
node containing subfields, and an onchange. Edit a row to trigger
the onchange. Before this rev., it crashed because the onchange
specs was incorrect: it followed the relation of the many2one
and thus included its subfields (whereas it should only follow the
relation for x2many fields).
For example, go to Accounting > Accounting > Sales and edit the
label of a move line.
Task 2044187
closesodoo/odoo#36001
Signed-off-by: Géry Debongnie (ged) <ged@openerp.com>