miniupnpd: 2.0.20180410 -> 2.0.20180422

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/miniupnpd/versions.

These checks were done:

- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- directory tree listing: https://gist.github.com/f8b4c06f4c61efa13671b5156550d7b5