[FIX] mass_mailing_sms : sms on record chatter

- For the sms marketing, by default the sms is now log
on the chatter of the record (like with the sms composer).
But can be disable it with keep arhives unchecked (in debug mode only).

TASK_ID : 2075733

addons/mass_mailing_sms/models/mailing_mailing.py

@@ -12,6 +12,13 @@ _logger = logging.getLogger(__name__)
 class Mailing(models.Model):
     _inherit = 'mailing.mailing'
 
+    @api.model
+    def default_get(self, fields):
+        res = super(Mailing, self).default_get(fields)
+        if fields is not None and 'keep_archives' in fields and res.get('mailing_type') == 'sms':
+            res['keep_archives'] = True
+        return res
+
     # mailing options
     mailing_type = fields.Selection(selection_add=[('sms', 'SMS')])
     # sms options