**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.

const ASTPtr &, const StorageMetadataPtr &, ContextPtr query_context, TableExclusiveLockHolder & table_lock)
{
    table_lock.release();   
    assertNotReadonly();
    if (!is_leader)
        throw Exception("TRUNCATE cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
    zkutil::ZooKeeperPtr zookeeper = getZooKeeper();
    Strings partitions = zookeeper->getChildren(fs::path(zookeeper_path) / "block_numbers");
    std::vector<std::unique_ptr<LogEntry>> entries_to_wait;
    entries_to_wait.reserve(partitions.size());
    for (String & partition_id : partitions)
    {
        auto entry = std::make_unique<LogEntry>();
        if (dropAllPartsInPartition(*zookeeper, partition_id, *entry, query_context, false))
            entries_to_wait.push_back(std::move(entry));
    }
    for (const auto & entry : entries_to_wait)
        waitForLogEntryToBeProcessedIfNecessary(*entry, query_context);
}
PartitionCommandsResultInfo StorageReplicatedMergeTree::attachPartition(