message: emit error if an error value is returned
diff: @@ -170,8 +170,13 @@ public:
  ENVOY_LOG(debug, "expr_evaluate error: {}", eval_status.status().message());
  return WasmResult::InternalFailure;
  }
  + auto value = eval_status.value();
  + if (value.IsError()) {
  + ENVOY_LOG(debug, "expr_evaluate value error: {}", value.ErrorOrDie()->message());
  + return WasmResult::InternalFailure;
  + }
  std::string result;
  - auto serialize_status = serializeValue(eval_status.value(), &result);
  + auto serialize_status = serializeValue(value, &result);
  if (serialize_status != WasmResult::Ok) {
  return serialize_status;
  }
  