**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
```
metadata_path = metadata_path / "store" / DatabaseCatalog::getPathForUUID(create.uuid);
    }
    else
    {
        bool is_on_cluster = getContext()->getClientInfo().query_kind == ClientInfo::QueryKind::SECONDARY_QUERY;
        if (create.uuid != UUIDHelpers::Nil && !is_on_cluster)
            throw Exception("Ordinary database engine does not support UUID", ErrorCodes::INCORRECT_QUERY);
        
        create.uuid = UUIDHelpers::Nil;
        metadata_path = metadata_path / "metadata" / database_name_escaped;
    }
    if (create.storage->engine->name == "MaterializeMySQL" && !getContext()->getSettingsRef().allow_experimental_database_materialize_mysql
        && !internal)
    {
        throw Exception("MaterializeMySQL is an experimental database engine. "
                        "Enable allow_experimental_database_materialize_mysql to use it.", ErrorCodes::UNKNOWN_DATABASE_ENGINE);
    }
    if (create.storage->engine->name == "Replicated" && !getContext()->getSettingsRef().allow_experimental_database_replicated && !internal)
    {
        throw Exception("Replicated is an experimental database engine. "
                        "Enable allow_experimental_database_replicated to use it.", ErrorCodes::UNKNOWN_DATABASE_ENGINE);
    }
    DatabasePtr database = DatabaseFactory::get(create, metadata_path / "", getContext());
    if (create.uuid != UUIDHelpers::Nil)
        create.database = TABLE_WITH_UUID_NAME_PLACEHOLDER;
    bool need_write_metadata = !create.attach || !fs::exists(metadata_file_path);
    if (need_write_metadata)
    {
        create.attach = true;
        create.if_not_exists = false;