**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.

"It means that part was successfully written to {} replicas, but then all of them goes offline. "
                                         "Or it is a bug.", entry.new_part_name, quorum_entry.part_name, entry.quorum);
                    }
                }
            }
            if (replica.empty())
            {
                ProfileEvents::increment(ProfileEvents::ReplicatedPartFailedFetches);
                throw Exception("No active replica has part " + entry.new_part_name + " or covering part", ErrorCodes::NO_REPLICA_HAS_PART);
            }
        }
        try
        {
            String part_name = entry.actual_new_part_name.empty() ? entry.new_part_name : entry.actual_new_part_name;
            if (!entry.actual_new_part_name.empty())
                LOG_DEBUG(log, "Will fetch part {} instead of {}", entry.actual_new_part_name, entry.new_part_name);
            if (!fetchPart(part_name, metadata_snapshot, fs::path(zookeeper_path) / "replicas" / replica, false, entry.quorum))
                return false;
        }
        catch (Exception & e)
        {
            
            if (e.code() == ErrorCodes::RECEIVED_ERROR_TOO_MANY_REQUESTS)
                e.addMessage("Too busy replica. Will try later.");
            throw;
        }
        if (entry.type == LogEntry::MERGE_PARTS)
            ProfileEvents::increment(ProfileEvents::ReplicatedPartFetchesOfMerged);
    }
    catch (...)