**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.

ColumnsDescription new_columns, const ReplicatedMergeTreeTableMetadata::Diff & metadata_diff)
{
    StorageInMemoryMetadata new_metadata = getInMemoryMetadata();
    StorageInMemoryMetadata old_metadata = getInMemoryMetadata();
    new_metadata.columns = new_columns;
    if (!metadata_diff.empty())
    {
        auto parse_key_expr = [] (const String & key_expr)
        {
            ParserNotEmptyExpressionList parser(false);
            auto new_sorting_key_expr_list = parseQuery(parser, key_expr, 0, DBMS_DEFAULT_MAX_PARSER_DEPTH);
            ASTPtr order_by_ast;
            if (new_sorting_key_expr_list->children.size() == 1)
                order_by_ast = new_sorting_key_expr_list->children[0];
            else
            {
                auto tuple = makeASTFunction("tuple");
                tuple->arguments->children = new_sorting_key_expr_list->children;
                order_by_ast = tuple;
            }
            return order_by_ast;
        };
        if (metadata_diff.sorting_key_changed)
        {