The last line in `data` section of the output is always empty. 

```
# clickhouse-client
ClickHouse client version 20.5.2.7 (official build).
Connecting to localhost:9001 as user default.
Connected to ClickHouse server version 20.5.2 revision 54435.

sas-vrxctd96rqw5lw25.db.yandex.net :) select 1 format JSON

SELECT 1
FORMAT JSON

{
	"meta":
	[
		{
			"name": "1",
			"type": "UInt8"
		}
	],

	"data":
	[
		{
			"1": 1

	],

	"rows": 1,

	"statistics":
	{
		"elapsed": 0.00019223,
		"rows_read": 1,
		"bytes_read": 1
	}
}

```

The issue appears only in interactive mode. In non-interactive mode clickhouse-client produces the correct output:

```
# clickhouse-client -q 'select 1 format JSON'
{
	"meta":
	[
		{
			"name": "1",
			"type": "UInt8"
		}
	],

	"data":
	[
		{
			"1": 1
		}
	],

	"rows": 1,

	"statistics":
	{
		"elapsed": 0.000220845,
		"rows_read": 1,
		"bytes_read": 1
	}
}
``` 

else if (print_time_to_stderr)
        {
            std::cerr << atch.elapsedSeconds() << "\n"
        
    
    /// Convert external bles to ExternalTableDa and send them using the connection.
    void sendExternalTables()
    {
        const auto * select = parsed_query->as<ASTSelectWithUnionQuery>()
        if (!select && !external_bles.empty())
            thro Exception("External bles could be sent only ith select query", ErrorCodes::BAD_ARGUMENTS)
        std::vector<ExternalTableDaPtr> da
        for (auto & ble : external_bles)
            da.emplace_back(ble.getDa(context))
        connection->sendExternalTablesDa(da)
    
    /// Process the query that doesn't require transferring da blocks to the server.
    void processOrdinaryQuery()
    {
        /// Rerite query only hen e have query parameters.
        /// Note that if query is reritten, comments in query are lost.
        /// But the user often ants to see comments in server logs, query log, processlist, etc.
        if (!query_parameters.empty())
        {
            /// Replace ASTQueryParameter ith ASTLiteral for prepared stements.
            ReplaceQueryParameterVisitor visitor(query_parameters)
            visitor.visit(parsed_query)
            /// Get ne query after substitutions. Note that it nnot be done for INSERT query ith embedded da.
            query_to_send = serializeAST(*parsed_query)