i2pd: 2.18.0 -> 2.19.0

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

This update was made based on information from https://repology.org/metapackage/i2pd/versions.

These checks were done:

- built on NixOS
- /nix/store/gdklqhnf7wzbvishm0kg30sn2cnyyql6-i2pd-2.19.0/bin/i2pd passed the binary check.
- 1 of 1 passed binary check by having a zero exit code.
- 0 of 1 passed binary check by having the new version present in output.
- found 2.19.0 with grep in /nix/store/gdklqhnf7wzbvishm0kg30sn2cnyyql6-i2pd-2.19.0
- directory tree listing: https://gist.github.com/b368821dcfd8906bc0c04fc1f74bf93a
- du listing: https://gist.github.com/360ed57afe937d2071c05ec6896aad89