libre: 0.5.6 -> 0.5.7

Semi-automatic update. These checks were performed:

- built on NixOS
- found 0.5.7 with grep in /nix/store/flnmjxr20pwpgi7d35361gh6xwai8d07-libre-0.5.7
- found 0.5.7 in filename of file in /nix/store/flnmjxr20pwpgi7d35361gh6xwai8d07-libre-0.5.7

cc "@raskin"