**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
```
{
    ASTPtr ast;
    bool has_table = tryGetTable(table_name, getContext()) != nullptr;
    auto table_metadata_path = getObjectMetadataPath(table_name);
    try
    {
        ast = getCreateQueryFromMetadata(table_metadata_path, throw_on_error);
    }
    catch (const Exception & e)
    {
        if (!has_table && e.code() == ErrorCodes::FILE_DOESNT_EXIST && throw_on_error)
            throw Exception{"Table " + backQuote(table_name) + " doesn't exist",
                            ErrorCodes::CANNOT_GET_CREATE_TABLE_QUERY};
        else if (throw_on_error)
            throw;
    }
    return ast;
}
ASTPtr DatabaseOnDisk::getCreateDatabaseQuery() const