log timestamping error on Link remove

Change-Id: Ia333fb4f9c4af3642482f626e5660e0339d13995

@@ -377,6 +377,7 @@ public class GossipLinkStore
         try {
             timestamp = deviceClockService.getTimestamp(dstDeviceId);
         } catch (IllegalStateException e) {
+            log.warn("Failed to remove link {}, was not the master", key);
             //there are times when this is called before mastership
             // handoff correctly completes.
             return null;