**Describe the bug**
The ClickHouse client freezes when executing `ALTER TABLE` with `ADD COLUMN` and `MODIFY ORDER` on a table built using Replicated Versioned Collapsing Merge Tree engine.

**How to reproduce**
* ClickHouse client version 20.10.1.1.
Connecting to localhost:9000 as user default.
Connected to ClickHouse server version 20.10.1 revision 54440.

* `CREATE TABLE` statements
```
SHOW CREATE TABLE table0

┌─statement──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ CREATE TABLE default.table0
(
    `d` Date,
    `a` String,
    `b` UInt8,
    `x` String,
    `y` Int8,
    `version` UInt64,
    `sign` Int8 DEFAULT 1
)
ENGINE = ReplicatedVersionedCollapsingMergeTree('/clickhouse/tables/{shard}/table0', '{replica}', sign, version)
PARTITION BY y
ORDER BY d
SETTINGS index_granularity = 8192 │
└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

1 rows in set. Elapsed: 0.004 sec.
```

* Queries to run that lead to unexpected result
```
ALTER TABLE table0 ADD COLUMN order UInt32, MODIFY ORDER BY (d, order)
```
zkutil::makeCreateRequest(
                block_id_path,
                part_name,  
                zkutil::CreateMode::Persistent));
    }
    
    if (storage_settings_ptr->use_minimalistic_part_header_in_zookeeper)
    {
        ops.emplace_back(zkutil::makeCreateRequest(
            replica_path + "/parts/" + part->name,
            ReplicatedMergeTreePartHeader::fromColumnsAndChecksums(part->getColumns(), part->checksums).toString(),
            zkutil::CreateMode::Persistent));
    }
    else
    {
        ops.emplace_back(zkutil::makeCreateRequest(
            replica_path + "/parts/" + part->name,
            "",
            zkutil::CreateMode::Persistent));
        ops.emplace_back(zkutil::makeCreateRequest(
            replica_path + "/parts/" + part->name + "/columns",
            part->getColumns().toString(),
            zkutil::CreateMode::Persistent));
        ops.emplace_back(zkutil::makeCreateRequest(
            replica_path + "/parts/" + part->name + "/checksums",
            getChecksumsForZooKeeper(part->checksums),
            zkutil::CreateMode::Persistent));
    }
}
ReplicatedMergeTreeAddress StorageReplicatedMergeTree::getReplicatedMergeTreeAddress() const