**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
```
ErrorCodes::TABLE_WAS_NOT_DROPPED);
        StorageReplicatedMergeTree::dropReplica(zookeeper, query.replica_zk_path, query.replica, log);
        LOG_INFO(log, "Dropped replica {}", remote_replica_path);
    }
    else
        throw Exception("Invalid query", ErrorCodes::LOGICAL_ERROR);
}
bool InterpreterSystemQuery::dropReplicaImpl(ASTSystemQuery & query, const StoragePtr & table)
{
    auto * storage_replicated = dynamic_cast<StorageReplicatedMergeTree *>(table.get());
    if (!storage_replicated)
        return false;
    StorageReplicatedMergeTree::Status status;
    auto zookeeper = getContext()->getZooKeeper();
    storage_replicated->getStatus(status);
    
    if (query.replica == status.replica_name)
        throw Exception("We can't drop local replica, please use `DROP TABLE` "
                        "if you want to clean the data and drop this replica", ErrorCodes::TABLE_WAS_NOT_DROPPED);
    
    
    
    if (zookeeper->exists(status.zookeeper_path + "/replicas/" + query.replica + "/is_active"))
        throw Exception("Can't drop replica: " + query.replica + ", because it's active",
                        ErrorCodes::TABLE_WAS_NOT_DROPPED);
    storage_replicated->dropReplica(zookeeper, status.zookeeper_path, query.replica, log);
    LOG_TRACE(log, "Dropped replica {} of {}", query.replica, table->getStorageID().getNameForLogs());
    return true;
}
void InterpreterSystemQuery::syncReplica(ASTSystemQuery &)