Merge PR OCA#353 into 12.0

Signed-off-by dreispt

Author: OCA-git-bot

account_credit_control/models/credit_control_line.py

@@ -174,7 +174,7 @@ def _prepare_from_move_line(self, move_line, level, controlling_date,
                                 open_amount, default_lines_vals):
         """ Create credit control line """
         channel = level.channel
-        partner = move_line.partner_id
+        partner = move_line.invoice_id.partner_id or move_line.partner_id
         # Fallback to letter
         if channel == 'email' and partner and not partner.email:
             channel = 'letter'