**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.

#include <Interpreters/Context.h>
#include <Interpreters/DDLTask.h>
#include <Interpreters/InterserverCredentials.h>
#include <Poco/DirectoryIterator.h>
#include <base/range.h>
#include <base/scope_guard.h>
#include <base/scope_guard_safe.h>
#include <algorithm>
#include <ctime>
#include <filesystem>
#include <iterator>
#include <numeric>
#include <thread>
#include <future>
#include <boost/algorithm/string/join.hpp>
namespace fs = std::filesystem;
namespace ProfileEvents
{
    extern const Event ReplicatedPartMerges;
    extern const Event ReplicatedPartMutations;
    extern const Event ReplicatedPartFailedFetches;
    extern const Event ReplicatedPartFetchesOfMerged;
    extern const Event ObsoleteReplicatedParts;
    extern const Event ReplicatedPartFetches;
    extern const Event DataAfterMergeDiffersFromReplica;
    extern const Event DataAfterMutationDiffersFromReplica;
    extern const Event CreatedLogEntryForMerge;
    extern const Event NotCreatedLogEntryForMerge;
    extern const Event CreatedLogEntryForMutation;
    extern const Event NotCreatedLogEntryForMutation;