Protect the RouteManagers threads from exceptions thrown by listeners

Change-Id: Ia260dcdcb83070939b96e4c7fb8d20baa0ae78a5

@@ -279,12 +279,15 @@ public class RouteManager implements ListenerService<RouteEvent, RouteListener>,
         }
 
         private void poll() {
-            try {
             while (true) {
+                try {
                     listener.event(queue.take());
-                }
                 } catch (InterruptedException e) {
                     log.info("Route listener event thread shutting down: {}", e.getMessage());
+                    break;
+                } catch (Exception e) {
+                    log.warn("Exception during route event handler", e);
+                }
             }
         }