Tweak nix config

nixos/roles/default.nix

@@ -59,6 +59,7 @@
       auto-optimise-store = true
       builders-use-substitutes = true
     '';
+    optimise.automatic = true;
   };
 
   systemd.services = let

nixos/roles/server/default.nix

@@ -2,9 +2,5 @@
 
   imports = [ ./init_ssh.nix ];
 
-  nix = {
-    #gc.automatic = true;
-    optimise.automatic = true;
-  };
 
 }

nixos/roles/standalone/default.nix

@@ -22,7 +22,7 @@
     gc = {
       automatic = true;
       dates = "Mon 4:00";
-      options = "--delete-older-than 7d";
+      options = "-d";
     };
   };