libsForQt5.qscintilla: 2.9.4 -> 2.10.3

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 2.10.3 with grep in /nix/store/2q8rpns7liydfjw0sfxmr4dqb6ydn7fh-qscintilla-qt5-2.10.3
- directory tree listing: https://gist.github.com/a8a71ce267574bdfa3cfb49ecd9d784e