**Describe the issue**
ClickHouse is unable to start up after upgrading from 20.8 to 21.8. 

There is a replicated table with `:` in zk path and it couldn't be loaded with:

`2021.09.15 03:49:58.435071 [ 633075 ] {} <Error> Application: DB::Exception: Unknown auxiliary ZooKeeper name '/test_prefix'. If it's required it can be added to the section <auxiliary_zookeepers> in config.xml: Cannot attach table `db1`.`table1` from metadata file /var/lib/clickhouse/metadata/db1/table1.sql from query ATTACH TABLE db1.table1 (`field1` String, `date` Date) ENGINE = ReplicatedMergeTree('/test_prefix:db1/{shard}/table1', '{replica}') PARTITION BY toMonth(date) PRIMARY KEY field1 ORDER BY field1 SETTINGS index_granularity = 8192: while loading database `db1` from path /var/lib/clickhouse/metadata/db1
`

**Expected behavior**
ClickHouse server is able to startup after upgrade without schema change. "test_prefix" in "/test_prefix:db1/{shard}/table1" is not interpreted as an auxiliary ZooKeeper name.

continue;
        }
        else
        {
            zkutil::KeeperMultiException::check(rc, ops, responses);
        }
    }
    std::sort(source_queue_names.begin(), source_queue_names.end());
    struct QueueEntryInfo
    {
        String data = {};
        Coordination::Stat stat = {};
        LogEntryPtr parsed_entry = {};
    };
    
    
    
    
    
    
    
    std::vector<QueueEntryInfo> source_queue;
    ActiveDataPartSet get_part_set{format_version};
    ActiveDataPartSet drop_range_set{format_version};
    {
        std::vector<zkutil::ZooKeeper::FutureGet> queue_get_futures;
        queue_get_futures.reserve(source_queue_names.size());
        for (const String & entry_name : source_queue_names)
            queue_get_futures.push_back(zookeeper->asyncTryGet(fs::path(source_path) / "queue" / entry_name));
        source_queue.reserve(source_queue_names.size());