[FIX] mail,test_mass_mailing: unblacklist with mass mailing

The optimization 2ccf0bd0 does not take into account that to
"unblacklist" a user, you have the archive the mail.blacklist record so
only mail.blacklist active records need to be taken into account.

Added test without the fix fails with:

    AssertionError: False is not true : MailTrace: email
    test.record.02@test.example.com (recipient res.partner(), state:
    sent, record: mailing.test.blacklist(166,)): found 0 records (1 expected)

opw-2536304

closes odoo/odoo#71239

X-original-commit: 8ffd8224
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>