enable backupswitcher by default

app/UI/Disk/Forms/UpdateForm.php

@@ -77,6 +77,7 @@ class UpdateForm extends BaseForm implements ClientArea
         if ($this->configuration()->isPermissionAdditionalDiskBackup())
         {
             $field = new Switcher('backup');
+            $field->setDefaultValue('on');
             $this->addField($field);
         }
     }