[FIX] Admin Interface (Admin page for plugins) : Fix of the missing of checkboxes that allow to enable or disable the paymentlist plugin and disable edit plugin icon

On the admin page to enable/disable plugins (tiki-admin.php), paymentlist is missing checkboxes; instead only this text is displayed: "paymentlist: Show details of payments. The payments considered may be restrained by user or date.". The result of this bug is that the plugin Paymentlist cannot be activated or de-activated or disable its edit plugin icon! In this merge request I've fixed that bug.

For more details on the bug, please see : https://dev.tiki.org/item7417 and https://avan.tech/item71290