**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.

Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
    std::vector<zkutil::ZooKeeper::FutureGet> futures;
    for (const String & source_replica_name : replicas)
    {
        
        if (source_replica_name == replica_name)
            continue;
        String source_replica_path = fs::path(zookeeper_path) / "replicas" / source_replica_name;
        
        
        futures.emplace_back(zookeeper->asyncTryGet(fs::path(source_replica_path) / "is_lost"));
        futures.emplace_back(zookeeper->asyncTryGet(fs::path(source_replica_path) / "log_pointer"));
        futures.emplace_back(zookeeper->asyncTryGet(fs::path(source_replica_path) / "queue"));
    }
    
    for (auto & future : futures)
        future.wait();
    Strings log_entries = zookeeper->getChildren(fs::path(zookeeper_path) / "log");
    size_t max_log_entry = 0;
    if (!log_entries.empty())
    {
        String last_entry = *std::max_element(log_entries.begin(), log_entries.end());
        max_log_entry = parse<UInt64>(last_entry.substr(strlen("log-")));
    }
    
    ++max_log_entry;
    size_t min_replication_lag = std::numeric_limits<size_t>::max();
    String source_replica;