Set webgui browser off by default

via alias. Addresses recent cern root issue.

Possibly option for a solution.

As introduced by @f.uhlig in today's software and discussed by @p.-a.loizeau and @m.shiroya

See https://indico.gsi.de/event/18677/

See https://root.cern/about/security/#2023-11-26-open-port-for-control-of-web-gui-allows-read-and-write-access-to-file-system