By deleting the temporary file immediately, even if vdeliver exits abnormally, the file is gone.
The command remove_all has been added. This allow one to delete all field from the current dialog and generate a new configuration.
So, if you don't know what is the web mode or have never configured your server to use it, there is no problem. (http://your_server:98)
If you are using it and allows some "less" trusted users to use it then upgrading to 1.26 is mandatory or disable web mode from Linuxconf/networking/misc/linuxconf network access: Unselect the first check-box.