nixos/radicale: Allow AF_UNIX for systemd log (NixOS#373893)

Author: erictapen

nixos/modules/services/networking/radicale.nix

@@ -205,6 +205,7 @@ in
         RestrictAddressFamilies = [
           "AF_INET"
           "AF_INET6"
+          "AF_UNIX" # To log with systemd
         ];
         RestrictNamespaces = true;
         RestrictRealtime = true;