netbsd 10 box, please enable extended attributes

[ThomasWaldmann]

netbsd 10 is short before release and will include support for extended attributes (EAs) and ACLs.

But, that is not on by default, one needs to change the fs type at install time from FFSv2 to FFSv2ea.

Would be cool if the future netbsd 10 vagrant box has extended attribute support enabled, because that is hard to enable afterwards (and guess not possible just using vagrant).

Thanks for maintaining these boxes!