Before this commit: when new snippet is drop in mass_mailing after first delete everything and exiting from codeview a traceback occurs. After this commit: Now, a new snippet can be dropped in empty mass_mailing. Task-3178818 closes odoo/odoo#129865 X-original-commit: 8e93f3c65ada549c51b841d1f39a3422be6f3e27 Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>