[tlbuild] Last icu update breaks build on NetBSD

[Karl Berry]

    -# if U_PLATFORM_USES_ONLY_WIN32_API || U_PLATFORM == U_PF_CYGWIN
    +# if U_PLATFORM_USES_ONLY_WIN32_API || U_PLATFORM == U_PF_CYGWIN || defined(__NetBSD__)

Installed, thanks. I hope it's also been sent upstream? -k