**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();
    return zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "parts" / part_name);
}
String StorageReplicatedMergeTree::findReplicaHavingPart(const String & part_name, bool active)
{
    auto zookeeper = getZooKeeper();
    Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
    
    std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
    LOG_TRACE(log, "Candidate replicas: {}", replicas.size());
    for (const String & replica : replicas)
    {
        
        if (replica == replica_name)
            continue;
        LOG_TRACE(log, "Candidate replica: {}", replica);
        if (checkReplicaHavePart(replica, part_name) &&
            (!active || zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active")))
            return replica;
        
    }
    return {};
}
String StorageReplicatedMergeTree::findReplicaHavingCoveringPart(LogEntry & entry, bool active)