i read this article: Protect phpMyAdmin On An ISPConfig 3 Server (Debian), the point is the url of the alias of phpmyadmin is on webalizer...e.g http://server-ip/webalizer show the url of the alias...
The alias /webalizer is not from ispconfig and not used by ispconfig, you can remove that. The webalizer statsistics from ispconfig are avalable under domain.tld/stats