nix-daemon: Bump the default number of build users

While it's annoying to pollute the user database with a lot of nixbld*
users, 10 users is really too low for many modern systems.

Changed files
+1 -1
nixos
modules
services
+1 -1
nixos/modules/services/misc/nix-daemon.nix
···
fi
'';
-
nix.nrBuildUsers = mkDefault (lib.max 10 cfg.maxJobs);
+
nix.nrBuildUsers = mkDefault (lib.max 32 cfg.maxJobs);
users.extraUsers = nixbldUsers;