**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.

requests.emplace_back(zkutil::makeCreateRequest(
            fs::path(mutations_path) / "", mutation_entry.toString(), zkutil::CreateMode::PersistentSequential));
        if (auto txn = query_context->getZooKeeperMetadataTransaction())
            txn->moveOpsTo(requests);
        Coordination::Responses responses;
        Coordination::Error rc = zookeeper->tryMulti(requests, responses);
        partition_block_numbers_holder.reset();
        if (rc == Coordination::Error::ZOK)
        {
            const String & path_created =
                dynamic_cast<const Coordination::CreateResponse *>(responses[1].get())->path_created;
            mutation_entry.znode_name = path_created.substr(path_created.find_last_of('/') + 1);
            LOG_TRACE(log, "Created mutation with ID {}", mutation_entry.znode_name);
            break;
        }
        else if (rc == Coordination::Error::ZBADVERSION)
        {
            
            if (query_context->getZooKeeperMetadataTransaction())
                throw Exception("Cannot execute alter, because mutations version was suddenly changed due to concurrent alter",
                                ErrorCodes::CANNOT_ASSIGN_ALTER);
            LOG_TRACE(log, "Version conflict when trying to create a mutation node, retrying...");
            continue;
        }
        else
            throw Coordination::Exception("Unable to create a mutation znode", rc);
    }
    waitMutation(mutation_entry.znode_name, query_context->getSettingsRef().mutations_sync);
}
void StorageReplicatedMergeTree::waitMutation(const String & znode_name, size_t mutations_sync) const