Mock server's mail channel write method is incorrect. It assumes the id of the channel will always be 20 while it could be anything. closes odoo/odoo#86860 X-original-commit: 96e732f6bbc7622d50c3a969f5c2bb44c85c2b48 Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>