**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.

UInt64 unexpected_parts_nonnew_rows = 0;
    UInt64 unexpected_parts_rows = 0;
    for (const auto & part : unexpected_parts)
    {
        if (part->info.level > 0)
        {
            ++unexpected_parts_nonnew;
            unexpected_parts_nonnew_rows += part->rows_count;
        }
        unexpected_parts_rows += part->rows_count;
    }
    const UInt64 parts_to_fetch_blocks = std::accumulate(parts_to_fetch.cbegin(), parts_to_fetch.cend(), 0,
        [&](UInt64 acc, const String& part_name)
        {
            if (const auto part_info = MergeTreePartInfo::tryParsePartName(part_name, format_version))
                return acc + part_info->getBlocksCount();
            LOG_ERROR(log, "Unexpected part name: {}", part_name);
            return acc;
        });
    /** We can automatically synchronize data,
      *  if the ratio of the total number of errors to the total number of parts (minimum - on the local filesystem or in ZK)
      *  is no more than some threshold (for example 50%).
      *
      * A large ratio of mismatches in the data on the filesystem and the expected data
      *  may indicate a configuration error (the server accidentally connected as a replica not from right shard).
      * In this case, the protection mechanism does not allow the server to start.
      */
    UInt64 total_rows_on_filesystem = 0;
    for (const auto & part : parts)
        total_rows_on_filesystem += part->rows_count;