message: Tolerate out-of-order SQLMoreResults() calls
diff: @@ -348,6 +348,11 @@ void Statement::executeQuery(IResultMutatorPtr && mutator) {
  }
  void Statement::requestNextPackOfResultSets(IResultMutatorPtr && mutator) {
  + result_set.reset();
  +
  + if (query.empty())
  + return;
  +
  const auto param_set_array_size = getEffectiveDescriptor(SQL_ATTR_APP_PARAM_DESC).getAttrAs<SQLULEN>(SQL_DESC_ARRAY_SIZE, 1);
  if (next_param_set >= param_set_array_size)
  return;
  @@ -541,7 +546,6 @@ bool Statement::advanceToNextResultSet() {
  mutator = result_set->releaseMutator();
  // TODO: add support of detecting next result set on the wire, when protocol allows it.
  - result_set.reset();
  requestNextPackOfResultSets(std::move(mutator));
  return hasResultSet();
  