Add preliminary fix for Nodes Stats API

This commit adds a preliminary fix for
elastic/elasticsearch#78311 that is, however,
not yet released as of 7.15.1.

See #1535

docker-compose.yml

@@ -1,6 +1,6 @@
 services:
   elasticsearch:
-    image: docker.elastic.co/elasticsearch/elasticsearch:${VERSION:-7.15.0}
+    image: docker.elastic.co/elasticsearch/elasticsearch:${VERSION:-7.15.1}
     hostname: elasticsearch
     environment:
       - cluster.name=elasticsearch
@@ -28,7 +28,7 @@ services:
     ports:
       - 9200:9200
   platinum:
-    image: docker.elastic.co/elasticsearch/elasticsearch:${VERSION:-7.15.0}
+    image: docker.elastic.co/elasticsearch/elasticsearch:${VERSION:-7.15.1}
     hostname: elasticsearch-platinum
     environment:
       - cluster.name=platinum

nodes_stats_test.go

@@ -20,8 +20,8 @@ func TestNodesStats(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if version == "7.15.0" {
-		t.Skip("skipping NodesStats test for 7.15.0 because of https://github.com/elastic/elasticsearch/issues/78311")
+	if version == "7.15.0" || version == "7.15.1" {
+		t.Skipf("skipping NodesStats test for %s because of https://github.com/elastic/elasticsearch/issues/78311", version)
 		return
 	}