ClusterMessagingProtocol: fix error message

Change-Id: I6123bfcbe1c668864691c87caaba0874fc3188e2
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocol.java b/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocol.java
index 0ba67cf..dc913bf 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocol.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/service/impl/ClusterMessagingProtocol.java
@@ -174,7 +174,7 @@
     public ProtocolClient createClient(TcpMember member) {
         ControllerNode remoteNode = getControllerNode(member.host(), member.port());
         checkNotNull(remoteNode,
-                     "A valid controller node is expected for %s:%s",
+                     "No matching ONOS Node for %s:%s",
                      member.host(), member.port());
         return new ClusterMessagingProtocolClient(
                 clusterCommunicator, clusterService.getLocalNode(), remoteNode);