**Describe the bug**
`SYSTEM KILL` does not shutdown the server when run in a docker environment. I used https://hub.docker.com/r/yandex/clickhouse-server/ instructions to setup the docker.

**How to reproduce**
* ClickHouse server version 20.12.4 revision 54442.
```
myrotk@altinity-qa-cosmic3:~$ docker pull yandex/clickhouse-server
Using default tag: latest
latest: Pulling from yandex/clickhouse-server
da7391352a9b: Pull complete
14428a6d4bcd: Pull complete
2c2d948710f2: Pull complete
076cd2c6a81e: Pull complete
201ea6cda8c8: Pull complete
0d7b4e598027: Pull complete
0d86a58e3639: Pull complete
3b78a4fd0f92: Pull complete
86d65487f611: Pull complete
dc82dea7d6fe: Pull complete
Digest: sha256:8f669dafd35eb527210cc77973ed927734dff2c2cafd345823c8c99769124fd1
Status: Downloaded newer image for yandex/clickhouse-server:latest
docker.io/yandex/clickhouse-server:latest

myrotk@altinity-qa-cosmic3:~$ docker run -d --name some-clickhouse-server --ulimit nofile=262144:262144 yandex/clickhouse-server
35603911ec6c5737f069a019a60d03270cefe78e52c77d1bc6ff33a0548ae97e

myrotk@altinity-qa-cosmic3:~$ docker run -it --rm --link some-clickhouse-server:clickhouse-server yandex/clickhouse-client --host clickhouse-server
Unable to find image 'yandex/clickhouse-client:latest' locally
latest: Pulling from yandex/clickhouse-client
f22ccc0b8772: Pull complete
3cf8fb62ba5f: Pull complete
e80c964ece6a: Pull complete
6f064a173914: Pull complete
37a06aaf9ee5: Pull complete
Digest: sha256:504e18bed5162a20bbff6071ca1b7c7baca1380d2e2755e4d6bf4bac7e534531
Status: Downloaded newer image for yandex/clickhouse-client:latest
ClickHouse client version 20.12.4.5 (official build).
Connecting to clickhouse-server:9000 as user default.
Connected to ClickHouse server version 20.12.4 revision 54442.

35603911ec6c :) SYSTEM KILL

SYSTEM KILL

Query id: 0da8cfef-36c8-4de9-8c12-3e9175c5aed0

Ok.

0 rows in set. Elapsed: 0.002 sec.

35603911ec6c :)



else if (!query.replica_zk_path.empty())
    {
        context.checkAccess(AccessType::SYSTEM_DROP_REPLICA);
        auto remote_replica_path = query.replica_zk_path  + "/replicas/" + query.replica;
        
        for (auto & elem : DatabaseCatalog::instance().getDatabases())
        {
            DatabasePtr & database = elem.second;
            for (auto iterator = database->getTablesIterator(context); iterator->isValid(); iterator->next())
            {
                if (auto * storage_replicated = dynamic_cast<StorageReplicatedMergeTree *>(iterator->table().get()))
                {
                    StorageReplicatedMergeTree::Status status;
                    storage_replicated->getStatus(status);
                    if (status.zookeeper_path == query.replica_zk_path)
                        throw Exception("There is a local table " + storage_replicated->getStorageID().getNameForLogs() +
                                        ", which has the same table path in ZooKeeper. Please check the path in query. "
                                        "If you want to drop replica of this table, use `DROP TABLE` "
                                        "or `SYSTEM DROP REPLICA 'name' FROM db.table`", ErrorCodes::TABLE_WAS_NOT_DROPPED);
                }
            }
        }
        auto zookeeper = context.getZooKeeper();
        bool looks_like_table_path = zookeeper->exists(query.replica_zk_path + "/replicas") ||
                                     zookeeper->exists(query.replica_zk_path + "/dropped");
        if (!looks_like_table_path)
            throw Exception("Specified path " + query.replica_zk_path + " does not look like a table path",
                            ErrorCodes::TABLE_WAS_NOT_DROPPED);
        if (zookeeper->exists(remote_replica_path + "/is_active"))
            throw Exception("Can't remove replica: " + query.replica + ", because it's active",