thepeg: 2.1.1 -> 2.1.2

Semi-automatic update. These checks were performed:

- built on NixOS
- ran `/nix/store/s8bdx22ycxz8j072244q8sng0jxh3sjc-thepeg-2.1.2/bin/setupThePEG help` got 0 exit code
- ran `/nix/store/s8bdx22ycxz8j072244q8sng0jxh3sjc-thepeg-2.1.2/bin/setupThePEG -v` and found version 2.1.2
- ran `/nix/store/s8bdx22ycxz8j072244q8sng0jxh3sjc-thepeg-2.1.2/bin/setupThePEG --version` and found version 2.1.2
- ran `/nix/store/s8bdx22ycxz8j072244q8sng0jxh3sjc-thepeg-2.1.2/bin/runThePEG -v` and found version 2.1.2
- ran `/nix/store/s8bdx22ycxz8j072244q8sng0jxh3sjc-thepeg-2.1.2/bin/runThePEG --version` and found version 2.1.2
- found 2.1.2 with grep in /nix/store/s8bdx22ycxz8j072244q8sng0jxh3sjc-thepeg-2.1.2

cc "@veprbl"