Demoting boy-cried-wolf log messages.

Change-Id: Idfb9b3178b79ab6b30af285c10a52b9f20dfbfe1
diff --git a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java
index 2d7e2e7..e7e5ffe 100644
--- a/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java
+++ b/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/RoleManager.java
@@ -92,7 +92,7 @@
             // ensuring that the only two roles sent to 1.0 switches with
             // Nicira role support, are MASTER and SLAVE
             roleToSend = OFNiciraControllerRole.ROLE_OTHER;
-            log.warn("Sending Nx Role.SLAVE to switch {}.", sw);
+            log.debug("Sending Nx Role.SLAVE to switch {}.", sw);
         }
         int xid = sw.getNextTransactionId();
         OFExperimenter roleRequest = OFFactories.getFactory(OFVersion.OF_10)