**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.

{
    std::lock_guard lock(shared->storage_policies_mutex);
    if (policy_name.empty())
    {
        shared->tmp_path = path;
        if (!shared->tmp_path.ends_with('/'))
            shared->tmp_path += '/';
        auto disk = std::make_shared<DiskLocal>("_tmp_default", shared->tmp_path, 0);
        shared->tmp_volume = std::make_shared<SingleDiskVolume>("_tmp_default", disk, 0);
    }
    else
    {
        StoragePolicyPtr tmp_policy = getStoragePolicySelector(lock)->get(policy_name);
        if (tmp_policy->getVolumes().size() != 1)
             throw Exception("Policy " + policy_name + " is used temporary files, such policy should have exactly one volume",
                             ErrorCodes::NO_ELEMENTS_IN_CONFIG);
        shared->tmp_volume = tmp_policy->getVolume(0);
    }
    if (shared->tmp_volume->getDisks().empty())
         throw Exception("No disks volume for temporary files", ErrorCodes::NO_ELEMENTS_IN_CONFIG);
    return shared->tmp_volume;
}
void Context::setBackupsVolume(const String & path, const String & policy_name)