v17.12.1

**Fixes**

- `ocrmypdf --version` and `ocrmypdf --help` printed to standard error
  instead of standard output, so `version=$(ocrmypdf --version)` came back
  empty and `ocrmypdf --help | less` showed nothing. OCRmyPDF redirects file
  descriptor 1 to standard error early in startup, before it parses the
  command line, so that a stray write from a plugin or a library cannot
  corrupt a PDF being written to standard output; argparse's own output was
  caught by that redirection too and is now routed back to the real standard
  output. Error messages continue to go to standard error. Broken since
  v17.8.0.