**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
```
if (isDictionaryExist(table_name))
        throw Exception(
            ErrorCodes::DICTIONARY_ALREADY_EXISTS, "Dictionary {}.{} already exists", backQuote(getDatabaseName()), backQuote(table_name));
    if (isTableExist(table_name, getContext()))
        throw Exception(
            ErrorCodes::TABLE_ALREADY_EXISTS, "Table {}.{} already exists", backQuote(getDatabaseName()), backQuote(table_name));
    String table_metadata_path = getObjectMetadataPath(table_name);
    if (create.attach_short_syntax)
    {
        
        removeDetachedPermanentlyFlag(local_context, table_name, table_metadata_path, true);
        attachTable(table_name, table, getTableDataPath(create));
        return;
    }
    if (!create.attach)
        checkMetadataFilenameAvailability(table_name);
    if (create.attach && Poco::File(table_metadata_path).exists())
    {
        ASTPtr ast_detached = parseQueryFromMetadata(log, local_context, table_metadata_path);
        auto & create_detached = ast_detached->as<ASTCreateQuery &>();
        
        if (create.uuid != create_detached.uuid)
            throw Exception(
                    ErrorCodes::TABLE_ALREADY_EXISTS,
                    "Table {}.{} already exist (detached permanently). To attach it back "
                    "you need to use short ATTACH syntax or a full statement with the same UUID",
                    backQuote(getDatabaseName()), backQuote(table_name));
    }