Removing reliance on topology last update time.

src/main/java/net/floodlightcontroller/devicemanager/internal/Device.java

@@ -260,8 +260,6 @@ public class Device implements IDevice {
             Integer port = cur.getSwitchPort();
             if (dpid == null || port == null ||
                 !deviceManager.isValidAttachmentPoint(dpid, port) ||
-                cur.getLastSeenTimestamp().
-                    before(topology.getLastUpdateTime()) ||
                 (prev != null && 
                 topology.isConsistent(prev.getSwitchDPID().longValue(),
                                       prev.getSwitchPort().shortValue(),