ShortcutFile does not create on missing cache directory

ShortcutFile should go to C:\Users\\\\\\.cache\icedtea-web\cache in my case, but it doesn't.

https://github.com/AdoptOpenJDK/IcedTea-Web/blob/1be00cff3993d6b74b9d99df2a49149f52b48ae3/core/src/main/java/net/sourceforge/jnlp/util/WindowsDesktopEntry.java#L156
Throws an exception "could not find the path specified".
Reason is that the path does only exist up to the icedtea-web directory. Cache directory hasn't been created yet.
This happens on a fresh OWS installation and opening a jnlp and it's linked resources from a samba network share on Windows. Paths inside the jnlp are `codebase="file://\\\\host/with/path/to/share/"` for example. OWS iterprets this as a "local path" and does not cache anything. Consequently the last level from the cache directory haven't been created yet.

Cache directory should be checked if exist before trying to create shortcutFile.