JDBC format of aggregation query with date_format adds unnecessary column

[galkk]

the query

POST _opendistro/_sql?format=jdbc
{
  "query": "SELECT date_format(utc_time, 'dd-MM-YYYY'), count(*)  from kibana_sample_data_logs group by date_format(utc_time, 'dd-MM-YYYY')"
}

Works but returns one more null column in result schema.

  "schema": [
    {
      "name": "date_format_1410573132",
      "type": "text"
    },
    {
      "name": "date_format_1025417136",
      "type": "text"
    },
    {
      "name": "COUNT(*)",
      "type": "long"
    }
  ],
  "total": 10,
  "datarows": [
    [
      "10-08-2018",
      null,
      244
    ],
    [

The JDBC result formatting is in the SQL plugin, so creating issue here