[IMP]project: Set default automatic generate email alias

- Task: https://www.odoo.com/web?&debug=#id=9335&view_type=form&model=project.task&action=333&active_id=131
- Pad: https://pad.odoo.com/p/r.Ga3BXVrvbXRhVysA
Why changing it ? If setting a default alias_name, it should be taken into account. This test should not be modified; if it fails there is something to solve :) .