**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.

{
    if (!config.getBool("dictionaries_lazy_load", true))
        static_cast<void>(getEmbeddedDictionariesImpl(true));
}
void Context::loadOrReloadDictionaries(const Poco::Util::AbstractConfiguration & config)
{
    bool dictionaries_lazy_load = config.getBool("dictionaries_lazy_load", true);
    auto patterns_values = getMultipleValuesFromConfig(config, "", "dictionaries_config");
    std::unordered_set<std::string> patterns(patterns_values.begin(), patterns_values.end());
    std::lock_guard lock(shared->external_dictionaries_mutex);
    auto & external_dictionaries_loader = getExternalDictionariesLoaderUnlocked();
    external_dictionaries_loader.enableAlwaysLoadEverything(!dictionaries_lazy_load);
    if (shared->external_dictionaries_config_repository)
    {
        shared->external_dictionaries_config_repository->updatePatterns(patterns);
        external_dictionaries_loader.reloadConfig(shared->external_dictionaries_config_repository->getName());
        return;
    }
    auto app_path = getPath();
    auto config_path = getConfigRef().getString("config-file", "config.xml");
    auto repository = std::make_unique<ExternalLoaderXMLConfigRepository>(app_path, config_path, patterns);
    shared->external_dictionaries_config_repository = repository.get();
    shared->dictionaries_xmls = external_dictionaries_loader.addConfigRepository(std::move(repository));
}
void Context::loadOrReloadUserDefinedExecutableFunctions(const Poco::Util::AbstractConfiguration & config)