fdk_aac: 0.1.5 -> 0.1.6

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 0.1.6 with grep in /nix/store/cp8yg64bk9zga197f0npsp23l1w23r1r-fdk-aac-0.1.6
- directory tree listing: https://gist.github.com/4a817b07a8c77aa7e3d16adb65f01186