**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
```
Poco::File(metadata_file_path).remove();
        return nullptr;
    }
    auto settings = local_context->getSettingsRef();
    ParserCreateQuery parser;
    const char * pos = query.data();
    std::string error_message;
    auto ast = tryParseQuery(parser, pos, pos + query.size(), error_message,  false,
                             "in file " + metadata_file_path,  false, 0, settings.max_parser_depth);
    if (!ast && throw_on_error)
        throw Exception(error_message, ErrorCodes::SYNTAX_ERROR);
    else if (!ast)
        return nullptr;
    auto & create = ast->as<ASTCreateQuery &>();
    if (!create.table.empty() && create.uuid != UUIDHelpers::Nil)
    {
        String table_name = Poco::Path(metadata_file_path).makeFile().getBaseName();
        table_name = unescapeForFileName(table_name);
        if (create.table != TABLE_WITH_UUID_NAME_PLACEHOLDER && logger)
            LOG_WARNING(
                logger,
                "File {} contains both UUID and table name. Will use name `{}` instead of `{}`",
                metadata_file_path,
                table_name,
                create.table);
        create.table = table_name;
    }
    return ast;
}
ASTPtr DatabaseOnDisk::getCreateQueryFromMetadata(const String & database_metadata_path, bool throw_on_error) const