libpst: 0.6.70 -> 0.6.71

Semi-automatic update. These checks were performed:

- built on NixOS
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/lspst -h` got 0 exit code
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/lspst -V` and found version 0.6.71
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/lspst -h` and found version 0.6.71
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/readpst -h` got 0 exit code
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/readpst -V` and found version 0.6.71
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/readpst -h` and found version 0.6.71
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/pst2ldif -h` got 0 exit code
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/pst2ldif -V` and found version 0.6.71
- ran `/nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71/bin/pst2ldif -h` and found version 0.6.71
- found 0.6.71 with grep in /nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71
- found 0.6.71 in filename of file in /nix/store/xlx0625qp0sh74bp7h2g786an5kmhv75-libpst-0.6.71

cc "@tohl"