**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.

size_t index_,
            const String & src_part_name_,
            const String & new_part_name_,
            const String & checksum_hex_,
            MergeTreeDataFormatVersion format_version)
            : index(index_)
            , src_part_name(src_part_name_)
            , src_part_info(MergeTreePartInfo::fromPartName(src_part_name_, format_version))
            , new_part_name(new_part_name_)
            , new_part_info(MergeTreePartInfo::fromPartName(new_part_name_, format_version))
            , checksum_hex(checksum_hex_)
        {
        }
        size_t index; 
        String src_part_name;
        MergeTreePartInfo src_part_info;
        String new_part_name;
        MergeTreePartInfo new_part_info;
        String checksum_hex;
        
        MutableDataPartPtr res_part;
        
        MergeTreePartInfo found_new_part_info;