**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.

if (part->getState() == DataPartState::Committed)
            active_parts_names.push_back(part->name);
        forgetPartAndMoveToDetached(part);
    }
    LOG_INFO(log, "Moved all parts to detached/");
    const bool is_first_replica = createTableIfNotExists(metadata_snapshot);
    LOG_INFO(log, "Created initial ZK nodes, replica is first: {}", is_first_replica);
    if (!is_first_replica)
        createReplica(metadata_snapshot);
    createNewZooKeeperNodes();
    LOG_INFO(log, "Created ZK nodes for table");
    is_readonly = false;
    has_metadata_in_zookeeper = true;
    if (is_first_replica)
        for (const String& part_name : active_parts_names)
            attachPartition(std::make_shared<ASTLiteral>(part_name), metadata_snapshot, true, getContext());
    LOG_INFO(log, "Attached all partitions, starting table");
    startup();
    are_restoring_replica.store(false);
}
void StorageReplicatedMergeTree::dropPartNoWaitNoThrow(const String & part_name)
{
    assertNotReadonly();
    if (!is_leader)
        throw Exception("DROP PART cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
    zkutil::ZooKeeperPtr zookeeper = getZooKeeper();
    LogEntry entry;
    dropPartImpl(zookeeper, part_name, entry,  false,  false);
}
void StorageReplicatedMergeTree::dropPart(const String & part_name, bool detach, ContextPtr query_context)