removes unused properties

the dsType property caused some confusion about what datasource is
beeing used. I just removed it since it not beeing used.

closes #10072

pkg/services/alerting/extractor_test.go

@@ -366,7 +366,6 @@ func TestAlertRuleExtraction(t *testing.T) {
 				          "steppedLine": false,
 				          "targets": [
 				            {
-				              "dsType": "influxdb",
 				              "groupBy": [
 				                {
 				                  "params": [
@@ -411,7 +410,6 @@ func TestAlertRuleExtraction(t *testing.T) {
 				              "tags": []
 				            },
 				            {
-				              "dsType": "influxdb",
 				              "groupBy": [
 				                {
 				                  "params": [

pkg/tsdb/influxdb/model_parser_test.go

@@ -20,7 +20,6 @@ func TestInfluxdbQueryParser(t *testing.T) {
 		Convey("can parse influxdb json model", func() {
 			json := `
         {
-        "dsType": "influxdb",
         "groupBy": [
           {
             "params": [
@@ -123,7 +122,6 @@ func TestInfluxdbQueryParser(t *testing.T) {
 		Convey("can part raw query json model", func() {
 			json := `
       {
-        "dsType": "influxdb",
         "groupBy": [
           {
             "params": [

public/app/plugins/datasource/elasticsearch/query_builder.ts

@@ -172,7 +172,6 @@ export class ElasticQueryBuilder {
   build(target, adhocFilters?, queryString?) {
     // make sure query has defaults;
     target.metrics = target.metrics || [{ type: 'count', id: '1' }];
-    target.dsType = 'elasticsearch';
     target.bucketAggs = target.bucketAggs || [{type: 'date_histogram', id: '2', settings: {interval: 'auto'}}];
     target.timeField =  this.timeField;
 

public/app/plugins/datasource/influxdb/influx_query.ts

@@ -19,7 +19,6 @@ export default class InfluxQuery {
     this.scopedVars = scopedVars;
 
     target.policy = target.policy || 'default';
-    target.dsType = 'influxdb';
     target.resultFormat = target.resultFormat || 'time_series';
     target.orderByTime = target.orderByTime || 'ASC';
     target.tags = target.tags || [];