Semi-automatic update. These checks were performed:
- built on NixOS
- ran `/nix/store/27q1wf9bs3qp60l2q0b2pyzf6ykijarj-fceux-2.2.3/bin/fceux -h` got 0 exit code
- ran `/nix/store/27q1wf9bs3qp60l2q0b2pyzf6ykijarj-fceux-2.2.3/bin/fceux --help` got 0 exit code
- ran `/nix/store/27q1wf9bs3qp60l2q0b2pyzf6ykijarj-fceux-2.2.3/bin/fceux -h` and found version 2.2.3
- ran `/nix/store/27q1wf9bs3qp60l2q0b2pyzf6ykijarj-fceux-2.2.3/bin/fceux --help` and found version 2.2.3
- found 2.2.3 with grep in /nix/store/27q1wf9bs3qp60l2q0b2pyzf6ykijarj-fceux-2.2.3
- found 2.2.3 in filename of file in /nix/store/27q1wf9bs3qp60l2q0b2pyzf6ykijarj-fceux-2.2.3
fceux needs lua 5.1; 5.2 seems to have introduced breaking API changes.
I removed the SYSTEM_LUA argument because we do want to build with the
system-provided lua, not the lua bundled in the fceux tarball.
