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
	}
}
``` 

* Split these groups before processing.
          */
        using Arguments = std::vector<std::string>
        Arguments common_arguments{""        /// 0th argument is ignored.
        std::vector<Arguments> 
        bool in_external_group = false
        for (int arg_num = 1 arg_num < argc ++arg_num)
        {
            const char * arg = argv[arg_num]
            if (0 == strcmp(arg, "--external"))
            {
                in_external_group = true
                external_bles_arguments.emplace_back(Arguments{"")
            
            /// Options ith value after equal sign.
            else if (in_external_group
                && (0 == strncmp(arg, "--file=", strlen("--file="))
                 || 0 == strncmp(arg, "--name=", strlen("--name="))
                 || 0 == strncmp(arg, "--format=", strlen("--format="))
                 || 0 == strncmp(arg, "--structure=", strlen("--structure="))
                 || 0 == strncmp(arg, "--types=", strlen("--types="))))
            {
                external_bles_arguments.back().emplace_back(arg)
            
            /// Options ith value after hitespace.
            else if (in_external_group
                && (0 == strcmp(arg, "--file")
                 || 0 == strcmp(arg, "--name")
                 || 0 == strcmp(arg, "--format")
                 || 0 == strcmp(arg, "--structure")