chgserver: remove Python 2 file descriptor logic Follows up 0bb28b7736bc "chgserver: remove Python 2 support code." On Python 2, we had to close newfp prior to restoring the original file description since "delete newfp" would otherwise close the file descriptor shared with the long-lived fp: in attachio(): newfp = os.fdopen(fp.fileno(), mode, bufsize) in _restoreio(): newfp.close() # temporarily close newfp.fileno() (= fp.fileno()) os.dup2(fd, fp.fileno()) # reopen fp.fileno() with original fd On the other hand, we shouldn't call newfp.close() on Python 3 since any function calls are proxied to the underlying file object by procutil.LineBufferedWrapper.