**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.

{
    try
    {
        shutdown();
    }
    catch (...)
    {
        tryLogCurrentException(__PRETTY_FUNCTION__);
    }
}
ReplicatedMergeTreeQuorumAddedParts::PartitionIdToMaxBlock StorageReplicatedMergeTree::getMaxAddedBlocks() const
{
    ReplicatedMergeTreeQuorumAddedParts::PartitionIdToMaxBlock max_added_blocks;
    for (const auto & data_part : getDataParts())
    {
        max_added_blocks[data_part->info.partition_id]
            = std::max(max_added_blocks[data_part->info.partition_id], data_part->info.max_block);
    }
    auto zookeeper = getZooKeeper();
    const String quorum_status_path = fs::path(zookeeper_path) / "quorum" / "status";
    String value;