opendht: 1.6.0 -> 1.6.1

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

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

These checks were done:

- built on NixOS
- ran `/nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1/bin/dhtnode -h` got 0 exit code
- ran `/nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1/bin/dhtnode --help` got 0 exit code
- ran `/nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1/bin/dhtchat -h` got 0 exit code
- ran `/nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1/bin/dhtchat --help` got 0 exit code
- ran `/nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1/bin/dhtscanner -h` got 0 exit code
- ran `/nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1/bin/dhtscanner --help` got 0 exit code
- found 1.6.1 with grep in /nix/store/8ma5flfjdkb4gs01vyc35mfmi2rzmm12-opendht-1.6.1
- directory tree listing: https://gist.github.com/2fabb2b68bb3484aee392ab952c5a428