nixos/tests/cloud-init: fix the erroring out
nixos/tests/cloud-init: fix the erroring out

The test was broken for a 1.5 months apparently? Well, now it passes.
Also apparently it's not flaky anymore.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs