Disable web frontend of piCorePlayer

Hello,

can someone give me a hint how to disable the web frontend of piCorePlayer after successful configuration?
I don't want anyone to change any setting after setup.
I have read that an older version (3?) had the option to disable web GUI, but I can not find this option in
the actual version. I have not problem changing configuration files, if this is necessary.

Thanks in advance,
Andreas