allegro: 5.2.3.0 -> 5.2.4.0

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 5.2.4.0 with grep in /nix/store/ffhc3yjpm6avrds564k83vgn1ppw00yr-allegro-5.2.4.0
- directory tree listing: https://gist.github.com/1045c5013f37df121b7965ce4f5c9f5a