**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.

{
        
        log->warning(message);
        warnings.push_back(message);
    }
};
Context::Context() = default;
Context::Context(const Context &) = default;
Context & Context::operator=(const Context &) = default;
SharedContextHolder::SharedContextHolder(SharedContextHolder &&) noexcept = default;
SharedContextHolder & SharedContextHolder::operator=(SharedContextHolder &&) = default;
SharedContextHolder::SharedContextHolder() = default;
SharedContextHolder::~SharedContextHolder() = default;
SharedContextHolder::SharedContextHolder(std::unique_ptr<ContextSharedPart> shared_context)
    : shared(std::move(shared_context)) {}
void SharedContextHolder::reset() { shared.reset(); }
ContextMutablePtr Context::createGlobal(ContextSharedPart * shared)
{
    auto res = std::shared_ptr<Context>(new Context);
    res->shared = shared;
    return res;
}
void Context::initGlobal()
{
    DatabaseCatalog::init(shared_from_this());
}
SharedContextHolder Context::createShared()