**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.

return;
    }
    auto metadata_snapshot = getInMemoryMetadataPtr();
    
    
    if (attach && !current_zookeeper->exists(replica_path))
    {
        LOG_WARNING(log, "No metadata in ZooKeeper for {}: table will be in readonly mode", replica_path);
        is_readonly = true;
        has_metadata_in_zookeeper = false;
        return;
    }
    if (!attach)
    {
        if (!getDataParts().empty())
            throw Exception("Data directory for table already contains data parts"
                " - probably it was unclean DROP table or manual intervention."
                " You must either clear directory by hand or use ATTACH TABLE"
                " instead of CREATE TABLE if you need to use that parts.", ErrorCodes::INCORRECT_DATA);
        try
        {
            bool is_first_replica = createTableIfNotExists(metadata_snapshot);
            try
            {
                
                
                
                
                other_replicas_fixed_granularity = checkFixedGranularityInZookeeper();
                checkTableStructure(zookeeper_path, metadata_snapshot);