Use Source Name as name, drop unused index (#701)

Author: Hor911

ydb/library/yql/providers/dq/actors/task_controller_impl.h

@@ -442,8 +442,7 @@ class TTaskControllerImpl: public NActors::TActor<TDerived> {
 
         for (const auto& stats : s.GetSources()) {
             auto labels = commonLabels;
-            labels["Source"] = ToString(stats.GetInputIndex());
-            labels["Name"] = stats.GetIngressName();
+            labels["Source"] = stats.GetIngressName();
             TaskStat.AddAsyncStats(stats.GetIngress(), labels, "Ingress");
             TaskStat.AddAsyncStats(stats.GetPush(),  labels, "Push");
             TaskStat.AddAsyncStats(stats.GetPop(), labels, "Pop");