remove deprecated isDurable() method

Change-Id: I000fe7dc49b6ba231cc7483cf0ad67593b50f06e
diff --git a/apps/optical/src/main/java/org/onosproject/optical/OpticalLinkProvider.java b/apps/optical/src/main/java/org/onosproject/optical/OpticalLinkProvider.java
index 1e32592..c042abb 100644
--- a/apps/optical/src/main/java/org/onosproject/optical/OpticalLinkProvider.java
+++ b/apps/optical/src/main/java/org/onosproject/optical/OpticalLinkProvider.java
@@ -119,7 +119,7 @@
 
     private void processDeviceLinks(Device device) {
         for (Link link : linkService.getDeviceLinks(device.id())) {
-            if (link.isDurable() && link.type() == OPTICAL) {
+            if (link.isExpected() && link.type() == OPTICAL) {
                 processLink(link);
             }
         }
@@ -128,7 +128,7 @@
     private void processPortLinks(Device device, Port port) {
         ConnectPoint connectPoint = new ConnectPoint(device.id(), port.number());
         for (Link link : linkService.getLinks(connectPoint)) {
-            if (link.isDurable() && link.type() == OPTICAL) {
+            if (link.isExpected() && link.type() == OPTICAL) {
                 processLink(link);
             }
         }