nix-daemon: Exit successfully when interrupted.
nix-daemon: Exit successfully when interrupted.

Fixes #2058.

dtzWill/nix,dezgeg/nix,dtzWill/nix,zimbatm/nix,ehmry/nix,layus/nix,ehmry/nix,layus/nix,NixOS/nix,NixOS/nix,layus/nix,NixOS/nix,rycee/nix,layus/nix,NixOS/nix,rycee/nix,dtzWill/nix,shlevy/nix,pikajude/nix,ehmry/nix,shlevy/nix,rycee/nix,dezgeg/nix,shlevy/nix,pikajude/nix,dtzWill/nix,dezgeg/nix,vcunat/nix,ehmry/nix,zimbatm/nix,rycee/nix,ehmry/nix,shlevy/nix,ehmry/nix,peti/nix,zimbatm/nix,rycee/nix,vcunat/nix,NixOS/nix,vcunat/nix,dezgeg/nix,pikajude/nix,peti/nix,shlevy/nix,zimbatm/nix,dtzWill/nix,vcunat/nix,peti/nix,peti/nix,peti/nix,layus/nix,dezgeg/nix