**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.

{
    auto zookeeper = getZooKeeper();
    
    String quorum_status_path = fs::path(zookeeper_path) / "quorum" / "status";
    if (is_parallel)
        quorum_status_path = fs::path(zookeeper_path) / "quorum" / "parallel" / part_name;
    
    const String quorum_last_part_path = fs::path(zookeeper_path) / "quorum" / "last_part";
    String value;
    Coordination::Stat stat;
    
    while (zookeeper->tryGet(quorum_status_path, value, &stat))
    {
        ReplicatedMergeTreeQuorumEntry quorum_entry(value);
        if (quorum_entry.part_name != part_name)
        {
            LOG_TRACE(log, "Quorum {}, already achieved for part {} current part {}",
                      quorum_status_path, part_name, quorum_entry.part_name);
            
            break;
        }
        quorum_entry.replicas.insert(replica_name);
        if (quorum_entry.replicas.size() >= quorum_entry.required_number_of_replicas)
        {
            
            LOG_TRACE(log, "Got {} replicas confirmed quorum {}, going to remove node",
                      quorum_entry.replicas.size(), quorum_status_path);
            Coordination::Requests ops;
            Coordination::Responses responses;