mopidy-iris: 3.14.0 -> 3.14.2

Semi-automatic update generated by https://github.com/ryantm/nix-update tools. 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.)
- found 3.14.2 with grep in /nix/store/anzim7y47xa3m530qzq91n9wl8ys1kk2-Mopidy-Iris-3.14.2
- directory tree listing: https://gist.github.com/96a0fc1d9812e5c4e6659fd37c7b21c6