before this commit the lot field is visible even without activating the lot and serial number feature from the settings. after this commit the field will be visible only when the feature is activated in the settings. closes odoo/odoo#117850 X-original-commit: 9c02bc50b46f6544b4696632274045fad751aad5 Related: odoo/enterprise#39400 Signed-off-by: William Henrotin (whe) <whe@odoo.com>