**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.

if (zookeeper->exists(zookeeper_path + "/dropped"))
        {
            
            
            
            LOG_WARNING(log, "Removing leftovers from table {} (this might take several minutes)", zookeeper_path);
            String drop_lock_path = zookeeper_path + "/dropped/lock";
            Coordination::Error code = zookeeper->tryCreate(drop_lock_path, "", zkutil::CreateMode::Ephemeral);
            if (code == Coordination::Error::ZNONODE || code == Coordination::Error::ZNODEEXISTS)
            {
                LOG_WARNING(log, "The leftovers from table {} were removed by another replica", zookeeper_path);
            }
            else if (code != Coordination::Error::ZOK)
            {
                throw Coordination::Exception(code, drop_lock_path);
            }
            else
            {
                auto metadata_drop_lock = zkutil::EphemeralNodeHolder::existing(drop_lock_path, *zookeeper);
                if (!removeTableNodesFromZooKeeper(zookeeper, zookeeper_path, metadata_drop_lock, log))
                {
                    
                    continue;
                }
            }
        }
        LOG_DEBUG(log, "Creating table {}", zookeeper_path);
        
        String metadata_str = ReplicatedMergeTreeTableMetadata(*this, metadata_snapshot).toString();