**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 (throw_if_noop)
                throw Exception("Part " + part_name
                                + " is currently participating in a background operation (mutation/merge)"
                                + ", try again later", ErrorCodes::PART_IS_TEMPORARILY_LOCKED);
            return false;
        }
        if (partIsLastQuorumPart(part->info))
        {
            if (throw_if_noop)
                throw Exception("Part " + part_name + " is last inserted part with quorum in partition. Cannot drop",
                                ErrorCodes::NOT_IMPLEMENTED);
            return false;
        }
        if (partIsInsertingWithParallelQuorum(part->info))
        {
            if (throw_if_noop)
                throw Exception("Part " + part_name + " is inserting with parallel quorum. Cannot drop",
                                ErrorCodes::NOT_IMPLEMENTED);
            return false;
        }
        Coordination::Requests ops;
        getClearBlocksInPartitionOps(ops, *zookeeper, part_info.partition_id, part_info.min_block, part_info.max_block);
        size_t clear_block_ops_size = ops.size();
        
        
        entry.type = LogEntry::DROP_RANGE;
        entry.source_replica = replica_name;