librelp: 1.2.15 -> 1.2.16 (#40664)

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

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

These checks were done:

- built on NixOS

- 0 of 0 passed binary check by having a zero exit code.
- 0 of 0 passed binary check by having the new version present in output.
- found 1.2.16 with grep in /nix/store/a6787dmhj4xpxwmqk8876gkyg00gr48h-librelp-1.2.16
- directory tree listing: https://gist.github.com/1f742ba05336ce792bdc905f5cd9dd4d
- du listing: https://gist.github.com/3677c4e01ab864cae128476ab579a776