**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)
        throw Exception(ErrorCodes::NO_SUCH_DATA_PART, "Part {} not found locally", part_name);
    if (part->uuid == UUIDHelpers::Nil)
        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Part {} does not have an uuid assigned and it can't be moved between shards", part_name);
    ReplicatedMergeTreeMergePredicate merge_pred = queue.getMergePredicate(zookeeper);
    
    
    {
        if (partIsLastQuorumPart(part->info))
        {
            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Part {} is last inserted part with quorum in partition. Would not be able to drop", part_name);
        }
        
        String out_reason;
        if (!merge_pred.canMergeSinglePart(part, &out_reason))
            throw Exception(ErrorCodes::PART_IS_TEMPORARILY_LOCKED, "Part is busy, reason: " + out_reason);
    }
    {
        
        checkTableStructure(to, getInMemoryMetadataPtr());
    }
    PinnedPartUUIDs src_pins;
    PinnedPartUUIDs dst_pins;
    {
        String s = zookeeper->get(zookeeper_path + "/pinned_part_uuids", &src_pins.stat);
        src_pins.fromString(s);
    }
    {
        String s = zookeeper->get(to + "/pinned_part_uuids", &dst_pins.stat);
        dst_pins.fromString(s);