Suppress stack trace due to a network timeout that can be recovered from

Change-Id: I93f741e194fb96e7f1a681cdc8463d453e2e2bbc
diff --git a/core/store/dist/src/main/java/org/onosproject/store/intent/impl/WorkPartitionManager.java b/core/store/dist/src/main/java/org/onosproject/store/intent/impl/WorkPartitionManager.java
index 337bc55..a21a8e9 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/intent/impl/WorkPartitionManager.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/intent/impl/WorkPartitionManager.java
@@ -150,7 +150,8 @@
         try {
             rebalance();
         } catch (Exception e) {
-            log.warn("Exception caught during rebalance task. Will retry in " + RETRY_AFTER_DELAY_SEC + " seconds", e);
+            log.warn("Exception caught during rebalance task. Will retry in " +
+                     RETRY_AFTER_DELAY_SEC + " seconds", e.getMessage());
             scheduleRebalance(RETRY_AFTER_DELAY_SEC);
         }
     }