message: [Smoke tests] Small refactor to config loading.
  Closes:
  Approved by: gregnazario
diff: @@ -1472,24 +1472,18 @@ fn test_consensus_key_rotation() {
  let mut swarm = TestEnvironment::new(5);
  swarm.validator_swarm.launch();
  - // Load the node configs
  - let node_configs: Vec<_> = swarm
  - .validator_swarm
  - .config
  - .config_files
  - .iter()
  - .map(|config_path| NodeConfig::load(config_path).unwrap())
  - .collect();
  + // Load a node config
  + let node_config =
  + NodeConfig::load(swarm.validator_swarm.config.config_files.first().unwrap()).unwrap();
  // Connect the operator tool to the first node's JSON RPC API
  - let node_config = (&node_configs).first().unwrap();
  let op_tool = OperationalTool::new(
  format!("http://127.0.0.1:{}", node_config.rpc.address.port()),
  ChainId::test(),
  );
  // Load validator's on disk storage
  - let backend = load_backend_storage(&node_config);
  + let backend = load_backend_storage(&&node_config);
  // Rotate the consensus key
  let (txn_ctx, new_consensus_key) = op_tool.rotate_consensus_key(&backend).unwrap();
  @@ -1519,24 +1513,18 @@ fn test_operator_key_rotation() {
  let mut swarm = TestEnvironment::new(5);
  swarm.validator_swarm.launch();
  - // Load the node configs
  - let node_configs: Vec<_> = swarm
  - .validator_swarm
  - .config
  - .config_files
  - .iter()
  - .map(|config_path| NodeConfig::load(config_path).unwrap())
  - .collect();
  + // Load a node config
  + let node_config =
  + NodeConfig::load(swarm.validator_swarm.config.config_files.first().unwrap()).unwrap();
  // Connect the operator tool to the first node's JSON RPC API
  - let node_config = (&node_configs).first().unwrap();
  let op_tool = OperationalTool::new(
  format!("http://127.0.0.1:{}", node_config.rpc.address.port()),
  ChainId::test(),
  );
  // Load validator's on disk storage
  - let backend = load_backend_storage(&node_config);
  + let backend = load_backend_storage(&&node_config);
  let (txn_ctx, _) = op_tool.rotate_operator_key(&backend).unwrap();
  let mut client = swarm.get_validator_client(0, None);
  @@ -1572,24 +1560,18 @@ fn test_network_key_rotation() {
  let mut swarm = TestEnvironment::new(5);
  swarm.validator_swarm.launch();
  - // Load the node configs
  - let node_configs: Vec<_> = swarm
  - .validator_swarm
  - .config
  - .config_files
  - .iter()
  - .map(|config_path| NodeConfig::load(config_path).unwrap())
  - .collect();
  + // Load a node config
  + let node_config =
  + NodeConfig::load(swarm.validator_swarm.config.config_files.first().unwrap()).unwrap();
  // Connect the operator tool to the first node's JSON RPC API
  - let node_config = (&node_configs).first().unwrap();
  let op_tool = OperationalTool::new(
  format!("http://127.0.0.1:{}", node_config.rpc.address.port()),
  ChainId::test(),
  );
  // Load validator's on disk storage
  - let backend = load_backend_storage(&node_config);
  + let backend = load_backend_storage(&&node_config);
  // Rotate the validator network key
  let (txn_ctx, new_network_key) = op_tool.rotate_validator_network_key(&backend).unwrap();
  