**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.

{
    return shared->system_profile_name;
}
String Context::getFormatSchemaPath() const
{
    return shared->format_schema_path;
}
void Context::setFormatSchemaPath(const String & path)
{
    shared->format_schema_path = path;
}
Context::SampleBlockCache & Context::getSampleBlockCache() const
{
    assert(hasQueryContext());
    return getQueryContext()->sample_block_cache;
}
bool Context::hasQueryParameters() const
{
    return !query_parameters.empty();
}
const NameToNameMap & Context::getQueryParameters() const
{
    return query_parameters;
}
void Context::setQueryParameter(const String & name, const String & value)
{
    if (!query_parameters.emplace(name, value).second)
        throw Exception("Duplicate name " + backQuote(name) + " of query parameter", ErrorCodes::BAD_ARGUMENTS);
}
void Context::addBridgeCommand(std::unique_ptr<ShellCommand> cmd) const