Convert Pro allows you to white label the plugin and show it as your own. You can read our white label settings article to know more.
Normally, the white label settings can be hidden by checking the respective box on the settings page. But, if your customer de-activates & activates the plugin, then the white label settings are visible again.
To avoid this and for adding extra security layer you can hide the White Label settings completely by declaring the below constant in the wp-config.php file at the root of your WordPress installation.
define( 'CP_HIDE_WHITE_LABEL', true);
Once this is done, the White label settings will be hidden forever.