opener: force copy on 'a'ppend if nlinks() returns 0 (issue1922) If pywin32 is not installed, 'os.lstat(pathname).st_nlink' is used for nlinks(), which is always zero for all files on Windows. To make sure we break up hardlinks if pywin32 is missing, we force nlink = 2 if nlinks() returns < 1. (this completely fixes issue1922)