[FIX] crm, mail, mass_mailing: default bounce

Set a default bounce to zero. Otherwise, if not set, filtering on the
number of bounces doesn't work correctly.

opw-744558

addons/crm/models/crm_lead.py

@@ -106,7 +106,7 @@ class Lead(models.Model):
     date_conversion = fields.Datetime('Conversion Date', readonly=True)
 
     # Messaging and marketing
-    message_bounce = fields.Integer('Bounce', help="Counter of the number of bounced emails for this contact")
+    message_bounce = fields.Integer('Bounce', help="Counter of the number of bounced emails for this contact", default=0)
 
     # Only used for type opportunity
     probability = fields.Float('Probability', group_operator="avg", default=lambda self: self._default_probability())

addons/mail/models/res_partner.py

@@ -18,7 +18,7 @@ class Partner(models.Model):
     _mail_flat_thread = False
     _mail_mass_mailing = _('Customers')
 
-    message_bounce = fields.Integer('Bounce', help="Counter of the number of bounced emails for this contact")
+    message_bounce = fields.Integer('Bounce', help="Counter of the number of bounced emails for this contact", default=0)
     opt_out = fields.Boolean(
         'Opt-Out', help="If opt-out is checked, this contact has refused to receive emails for mass mailing and marketing campaign. "
                         "Filter 'Available for Mass Mailing' allows users to filter the partners when performing mass mailing.")

addons/mass_mailing/models/mass_mailing.py

@@ -77,7 +77,7 @@ class MassMailingContact(models.Model):
         'contact_id', 'list_id', string='Mailing Lists')
     opt_out = fields.Boolean(string='Opt Out', help='The contact has chosen not to receive mails anymore from this list')
     unsubscription_date = fields.Datetime(string='Unsubscription Date')
-    message_bounce = fields.Integer(string='Bounced', help='Counter of the number of bounced emails for this contact.')
+    message_bounce = fields.Integer(string='Bounced', help='Counter of the number of bounced emails for this contact.', default=0)
     country_id = fields.Many2one('res.country', string='Country')
     tag_ids = fields.Many2many('res.partner.category', string='Tags')