Don't build pop3 resource on Windows
Currently it fails due to using ssize_t which Windows doesn't know
We don't have KMail on Windows anyway at this point, but we still want other resources from kdepim-runtime for e.g. Kalendar
Currently it fails due to using ssize_t which Windows doesn't know
We don't have KMail on Windows anyway at this point, but we still want other resources from kdepim-runtime for e.g. Kalendar