unprotect: don't copy file if not hardlink or symlink

[efiop]

We can easily detect if it is a hardlink by checking a number of hardlinks with os.stat(it should be equal to 1).

NOTE: i don't think you can use stat().st_nlink > 1 on windows to detect hardlinks.

NOTE: should use our link list in state db to make sure that it is indeed our link.