**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.

storage_settings_ptr->max_replicated_merges_in_queue, merges_and_mutations_sum);
            UInt64 max_source_part_size_for_mutation = merger_mutator.getMaxSourcePartSizeForMutation();
            bool merge_with_ttl_allowed = merges_and_mutations_queued.merges_with_ttl < storage_settings_ptr->max_replicated_merges_with_ttl_in_queue &&
                getTotalMergesWithTTLInMergeList() < storage_settings_ptr->max_number_of_merges_with_ttl_in_pool;
            auto future_merged_part = std::make_shared<FutureMergedMutatedPart>();
            if (storage_settings.get()->assign_part_uuids)
                future_merged_part->uuid = UUIDHelpers::generateV4();
            if (max_source_parts_size_for_merge > 0 &&
                merger_mutator.selectPartsToMerge(future_merged_part, false, max_source_parts_size_for_merge, merge_pred, merge_with_ttl_allowed, nullptr) == SelectPartsDecision::SELECTED)
            {
                create_result = createLogEntryToMergeParts(
                    zookeeper,
                    future_merged_part->parts,
                    future_merged_part->name,
                    future_merged_part->uuid,
                    future_merged_part->type,
                    deduplicate,
                    deduplicate_by_columns,
                    nullptr,
                    merge_pred.getVersion(),
                    future_merged_part->merge_type);
            }
            
            else if (max_source_part_size_for_mutation > 0 && queue.countMutations() > 0
                     && merges_and_mutations_queued.mutations < storage_settings_ptr->max_replicated_mutations_in_queue)
            {
                
                DataPartsVector data_parts = getDataPartsVector();
                for (const auto & part : data_parts)
                {