social/mass_mailing_custom_unsubscribe/data/install_salt.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- © 2016 Jairo Llopis <jairo.llopis@tecnativa.com>
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->

<openerp>
<data noupdate="1">

<function model="mail.mass_mailing" name="_init_salt_create"/>

</data>
</openerp>