**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.

new_ops.emplace_back(zkutil::makeRemoveRequest(part_path, -1));
            }
            
            new_ops.insert(new_ops.end(), ops.begin(), ops.end());
            ops = std::move(new_ops);
        }
        try
        {
            zookeeper->multi(ops);
            return transaction.commit();
        }
        catch (const zkutil::KeeperMultiException & e)
        {
            size_t num_check_ops = 2 * absent_part_paths_on_replicas.size();
            size_t failed_op_index = e.failed_op_index;
            if (failed_op_index < num_check_ops && e.code == Coordination::Error::ZNODEEXISTS)
            {
                LOG_INFO(log, "The part {} on a replica suddenly appeared, will recheck checksums", e.getPathForFirstFailedOp());
            }
            else
                throw;
        }
    }
}
String StorageReplicatedMergeTree::getChecksumsForZooKeeper(const MergeTreeDataPartChecksums & checksums) const
{
    return MinimalisticDataPartChecksums::getSerializedString(checksums,
        getSettings()->use_minimalistic_checksums_in_zookeeper);
}
MergeTreeData::MutableDataPartPtr StorageReplicatedMergeTree::attachPartHelperFoundValidPart(const LogEntry& entry) const