I think the Web Administration option is one of the default ones, so not sure if you can disable it.
You can use attribute 'WebAdminURL' (0x3d007d) and remove all the text - default seems to have
http://<0x12d7f>
as default, so you can just change the http:// to https://
You might be able to look at some of the permissions and disable the Web Administration but haven't ever needed to do this. I'll check it out if this is possible.
Customising the xml files might be another option (OneClick Customisation).
Regards,
Frank