I haven't double checked but I was checking settings in conjunction with https://github.com/civicrm/civicrm-core/pull/13048 & I'm pretty sure you will have an enotice on yours as $_settings is not defined - I would recommend changing from extends CRM_Admin_Form_Setting to just CRM_Core_Form - you are not really using functionality from the settings form and it's not really supported as an integration point - I think it could well be completely deleted in the future
Note I recommend the same action for com.cividesk.normalize & com.cividesk.helptab
I haven't double checked but I was checking settings in conjunction with https://github.com/civicrm/civicrm-core/pull/13048 & I'm pretty sure you will have an enotice on yours as $_settings is not defined - I would recommend changing from extends CRM_Admin_Form_Setting to just CRM_Core_Form - you are not really using functionality from the settings form and it's not really supported as an integration point - I think it could well be completely deleted in the future
Note I recommend the same action for com.cividesk.normalize & com.cividesk.helptab