Gaiden Wrapper on Windows

[yamkazu]

following error occurs when downloading wrapper:

Exception in thread "main" java.lang.UnsupportedOperationException
        at java.nio.file.Files.setPosixFilePermissions(Files.java:1991)
        at gaiden.GaidenWrapper.download(GaidenWrapper.java:74)
        at gaiden.GaidenWrapper.getGaidenHome(GaidenWrapper.java:61)
        at gaiden.GaidenWrapper.run(GaidenWrapper.java:50)
        at gaiden.GaidenWrapper.main(GaidenWrapper.java:40)