This makes possible to use nextcloud-occ for setting extra
configuration options.

Example:

systemd.services.nextcloud-setup = {
  script = mkAfter ''
    nextcloud-occ config:system:set redis 'host' --value '/var/run/redis/redis.sock' --type string
    nextcloud-occ config:system:set redis 'port' --value 0 --type integer
  '';
};

Motivation for this change

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

cc @