deepin.deepin-gtk-theme: 17.10.5 -> 17.10.6

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 17.10.6 with grep in /nix/store/ga3bv13qx17rpki527kh2wzmb8ri5h5w-deepin-gtk-theme-17.10.6
- directory tree listing: https://gist.github.com/8406a3329d9f397b5fe75ab8f0eea6ad