**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();
    if (name == "profile")
    {
        setCurrentProfile(value.safeGet<String>());
        return;
    }
    settings.set(std::string_view{name}, value);
    if (name == "readonly" || name == "allow_ddl" || name == "allow_introspection_functions")
        calculateAccessRights();
}
void Context::applySettingChange(const SettingChange & change)
{
    try
    {
        setSetting(change.name, change.value);
    }
    catch (Exception & e)
    {
        e.addMessage(fmt::format("in attempt to set the value of setting '{}' to {}",
                                 change.name, applyVisitor(FieldVisitorToString(), change.value)));
        throw;
    }
}
void Context::applySettingsChanges(const SettingsChanges & changes)