Don't use pkg-config on windows

    let include_dir = env::var("OPENSSL_INCLUDE_DIR").ok();

    if lib_dir.is_none() && include_dir.is_none() {

        // rustc doesn't seem to work with pkg-config's output in mingw64

        if !target.contains("windows") {

            if let Ok(info) = pkg_config::find_library("openssl") {

                build_openssl_shim(&info.include_paths);

                return;

            }

        }

        if let Some(mingw_paths) = get_mingw_in_path() {

            for path in mingw_paths {

                println!("cargo:rustc-flags=-L native={}", path);