**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.

ReplicatedMergeTreeMutationEntry mutation_entry;
    mutation_entry.source_replica = replica_name;
    mutation_entry.commands = commands;
    const String mutations_path = fs::path(zookeeper_path) / "mutations";
    const auto zookeeper = getZooKeeper();
    
    
    
    while (true)
    {
        Coordination::Stat mutations_stat;
        zookeeper->get(mutations_path, &mutations_stat);
        PartitionBlockNumbersHolder partition_block_numbers_holder =
                allocateBlockNumbersInAffectedPartitions(mutation_entry.commands, query_context, zookeeper);
        mutation_entry.block_numbers = partition_block_numbers_holder.getBlockNumbers();
        mutation_entry.create_time = time(nullptr);
        
        
        
        Coordination::Requests requests;
        requests.emplace_back(zkutil::makeSetRequest(mutations_path, String(), mutations_stat.version));