defiant: Enable postgresql backups

hosts/defiant/services/postgresql.nix

@@ -6,10 +6,12 @@
   };
 
   services.postgresqlBackup = {
-    # enable = true;
+    enable = true;
     location = "/data/backup/postgresql/";
     startAt = "*-*-* 03:15:00";
-    backupAll = true;
+
+    # Each service is registered in its own configuration file
+    databases = [ ];
   };
 
   environment.systemPackages = [ config.services.postgresql.package ];