Previously to commit [1] notification emails were send using the after commit
hook (see [2] for related code move and [3] for original code). That commit
changed the parameter default value without any reason, meaning this mechanism
is not used anymore. This commit fixes that behavior.
[1] See commit 581a74143e: code cleaning
[2] See commit 7a6269719f: code move
[3] See commit 38e181ee2c: use of post-commit hook in mail
closesodoo/odoo#34645
Signed-off-by: Xavier Dollé (xdo) <xdo@odoo.com>