message: 1646: Add logging
diff: @@ -862,6 +862,7 @@ fn serialize_body(payment: &ExecutableDeployItem, session: &ExecutableDeployItem
  // asymmetric_key signing verification.
  fn validate_deploy(deploy: &Deploy) -> Result<(), DeployValidationFailure> {
  if deploy.approvals.is_empty() {
  + warn!(?deploy, "deploy has no approvals");
  return Err(DeployValidationFailure::EmptyApprovals);
  }
  let serialized_body = serialize_body(&deploy.payment, &deploy.session);
  @@ -878,9 +879,6 @@ fn validate_deploy(deploy: &Deploy) -> Result<(), DeployValidationFailure> {
  return Err(DeployValidationFailure::InvalidDeployHash);
  }
  - // We don't need to check for an empty set here. EE checks that the correct number and weight of
  - // signatures are provided when executing the deploy, so all we need to do here is check that
  - // any provided signatures are valid.
  for (index, approval) in deploy.approvals.iter().enumerate() {
  if let Err(error) = crypto::verify(&deploy.hash, &approval.signature, &approval.signer) {
  warn!(?deploy, "failed to verify approval {}: {}", index, error);
  