wip - workaround, create old clusterstate.json.

Took 3 minutes
diff --git a/solr/core/src/java/org/apache/solr/cloud/ZkController.java b/solr/core/src/java/org/apache/solr/cloud/ZkController.java
index 2a78b18..2884dbb 100644
--- a/solr/core/src/java/org/apache/solr/cloud/ZkController.java
+++ b/solr/core/src/java/org/apache/solr/cloud/ZkController.java
@@ -840,6 +840,8 @@
 
     paths.put(ZkStateReader.ROLES, emptyJson);
 
+    paths.put("/clusterstate.json", emptyJson);
+
 
     paths.put(COLLECTIONS_ZKNODE, null);
 //