Eero Aaltonen

Fixed commit message.

https://gitlab.kitware.com/cmake/cmake/-/issues/25196 seems like a/the relevant CMake issue. As far as I can tell, at the moment this is "just" a warning. So merge choice here would according to how much...

I changed the commit so that the warning/error is silenced using a gcc pragma instead. Would you find that acceptable?

@jaredgrubb Care to take a look? By suppressing the warning the library could be used also by code that compiles with `switch-default`.

@hennadii2012 : try to clear the `upndomain` (_set it to empty string,_ ""). I couldn't get username login to work with upndomain set.