nixos/ddclient: don't chown secrets until dynamicuser issue is resolved

[Mic92]

revert if #154928 or a similar fix gets applied

Motivation for this change

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.05 Release Notes (or backporting 21.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[arcnmx]

This just reverts a change that silenced a warning - /run/${RuntimeDirectory} still has the correct permissions to my knowledge (can you confirm this @Mic92?). This is the exact same diff I originally applied locally in response to encountering the error, so lgtm! The fact that it currently fails in such a way without any indication to the user of what the real problem is (and led me to make false assumptions about systemd) really sucks. You would think systemd would provide something like $UID to pre-exec hooks to prevent this from being a problem...

That said, *shrug*, now that we know what the problem is and how to work around it, it seems likely that more services are unknowingly affected - and the root cause should definitely be fixed more generally such as via the linked PR.