nixos/heapster: fix username

Broken in 1d61efb7f177f7b70c467ab4940fde0a3481d4dc.

Changed files
+1 -1
nixos
modules
services
monitoring
+1 -1
nixos/modules/services/monitoring/heapster.nix
···
};
};
-
users.users.heapsterrs = {
+
users.users.heapster = {
uid = config.ids.uids.heapster;
description = "Heapster user";
};