**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 <Common/Config/AbstractConfigurationComparison.h>
#include <Common/ZooKeeper/ZooKeeper.h>
#include <Common/ShellCommand.h>
#include <Common/TraceCollector.h>
#include <base/logger_useful.h>
#include <base/EnumReflection.h>
#include <Common/RemoteHostFilter.h>
#include <Interpreters/AsynchronousInsertQueue.h>
#include <Interpreters/DatabaseCatalog.h>
#include <Interpreters/JIT/CompiledExpressionCache.h>
#include <Storages/MergeTree/BackgroundJobsAssignee.h>
#include <Storages/MergeTree/MergeTreeBackgroundExecutor.h>
#include <Storages/MergeTree/MergeTreeDataPartUUID.h>
#include <Interpreters/SynonymsExtensions.h>
#include <Interpreters/Lemmatizers.h>
#include <filesystem>
namespace fs = std::filesystem;
namespace ProfileEvents
{
    extern const Event ContextLock;
    extern const Event CompiledCacheSizeBytes;
}
namespace CurrentMetrics
{
    extern const Metric ContextLockWait;
    extern const Metric BackgroundMovePoolTask;
    extern const Metric BackgroundSchedulePoolTask;
    extern const Metric BackgroundBufferFlushSchedulePoolTask;
    extern const Metric BackgroundDistributedSchedulePoolTask;
    extern const Metric BackgroundMessageBrokerSchedulePoolTask;