**How to reproduce**
Clickhouse version 21.5

```
cat /etc/clickhouse-server/users.xml
<?xml version="1.0"?>
<yandex>
    <!-- Profiles of settings. -->
    <profiles>
        <!-- Default settings. -->
        <default>
            <data_type_default_nullable>1</data_type_default_nullable>
            <load_balancing>random</load_balancing>
        </default>
....

2021.04.04 01:23:42.453678 [ 29048 ] {} <Error> Application: DB::Exception: Nested type Array(UInt64) cannot be inside Nullable type: Cannot attach table `system`.`crash_log` from metadata file /var/lib/clickhouse/metadata/system/crash_log.sql from query ATTACH TABLE system.crash_log (`event_date` Date, `event_time` DateTime, `timestamp_ns` UInt64, `signal` Int32, `thread_id` UInt64, `query_id` String, `trace` Array(UInt64), `trace_full` Array(String), `version` String, `revision` UInt32, `build_id` String) ENGINE = MergeTree ORDER BY (event_date, event_time) SETTINGS index_granularity = 8192: while loading database `system` from path /var/lib/clickhouse/metadata/system
```
: WithContext(context_), query_ptr(query_ptr_)
{
}
BlockIO InterpreterCreateQuery::createDatabase(ASTCreateQuery & create)
{
    String database_name = create.database;
    auto guard = DatabaseCatalog::instance().getDDLGuard(database_name, "");
    
    if (DatabaseCatalog::instance().isDatabaseExist(database_name))
    {
        if (create.if_not_exists)
            return {};
        else
            throw Exception("Database " + database_name + " already exists.", ErrorCodes::DATABASE_ALREADY_EXISTS);
    }
    
    String database_name_escaped = escapeForFileName(database_name);
    fs::path metadata_path = fs::canonical(getContext()->getPath());
    fs::path metadata_file_tmp_path = metadata_path / "metadata" / (database_name_escaped + ".sql.tmp");
    fs::path metadata_file_path = metadata_path / "metadata" / (database_name_escaped + ".sql");
    if (!create.storage && create.attach)
    {
        if (!fs::exists(metadata_file_path))
            throw Exception("Database engine must be specified for ATTACH DATABASE query", ErrorCodes::UNKNOWN_DATABASE_ENGINE);
        
        auto ast = DatabaseOnDisk::parseQueryFromMetadata(nullptr, getContext(), metadata_file_path);
        create = ast->as<ASTCreateQuery &>();
        if (!create.table.empty() || !create.storage)