gramps: 4.2.6 -> 4.2.8

Semi-automatic update. These checks were done:

- built on NixOS
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/gramps -h` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/gramps --help` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/gramps help` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/gramps -v` and found version 4.2.8
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/gramps --version` and found version 4.2.8
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/..gramps-wrapped-wrapped -h` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/..gramps-wrapped-wrapped --help` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/..gramps-wrapped-wrapped help` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/..gramps-wrapped-wrapped -v` and found version 4.2.8
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/..gramps-wrapped-wrapped --version` and found version 4.2.8
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/.gramps-wrapped -h` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/.gramps-wrapped --help` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/.gramps-wrapped help` got 0 exit code
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/.gramps-wrapped -v` and found version 4.2.8
- ran `/nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8/bin/.gramps-wrapped --version` and found version 4.2.8
- found 4.2.8 with grep in /nix/store/wpccn0mfc52ia42cx83v2q7irnvi99gg-gramps-4.2.8