**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.

{
    auto lock = getLock();
    return shared->user_scripts_path;
}
std::vector<String> Context::getWarnings() const
{
    auto lock = getLock();
    return shared->warnings;
}
VolumePtr Context::getTemporaryVolume() const
{
    auto lock = getLock();
    return shared->tmp_volume;
}
void Context::setPath(const String & path)
{
    auto lock = getLock();
    shared->path = path;
    if (shared->tmp_path.empty() && !shared->tmp_volume)
        shared->tmp_path = shared->path + "tmp/";
    if (shared->flags_path.empty())
        shared->flags_path = shared->path + "flags/";
    if (shared->user_files_path.empty())
        shared->user_files_path = shared->path + "user_files/";
    if (shared->dictionaries_lib_path.empty())
        shared->dictionaries_lib_path = shared->path + "dictionaries_lib/";
    if (shared->user_scripts_path.empty())
        shared->user_scripts_path = shared->path + "user_scripts/";
}
VolumePtr Context::setTemporaryStorage(const String & path, const String & policy_name)