[FIX] base: correctly delete required many2one
[FIX] base: correctly delete required many2one

In the transient model 'Change Password Wizard User', the many2one
`wizard_id` was not set as ondelete cascade even though this field was
required.

This was causing issues in the auto-vacuum cron if by chance this model
was cleaned up before the wizard ('Change Password Wizard').

Courtesy of @rco-odoo

Issue #813289

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo