Fix missing unsetDelegate call

Change-Id: Ifc1c93f4ab32363ed27bcd97cc0ce3dba187e6af
diff --git a/incubator/net/src/main/java/org/onosproject/incubator/net/mcast/impl/MulticastRouteManager.java b/incubator/net/src/main/java/org/onosproject/incubator/net/mcast/impl/MulticastRouteManager.java
index bbc8bdb..e7fa0a2 100644
--- a/incubator/net/src/main/java/org/onosproject/incubator/net/mcast/impl/MulticastRouteManager.java
+++ b/incubator/net/src/main/java/org/onosproject/incubator/net/mcast/impl/MulticastRouteManager.java
@@ -63,6 +63,7 @@
 
     @Deactivate
     public void deactivate() {
+        store.unsetDelegate(delegate);
         eventDispatcher.removeSink(McastEvent.class);
         log.info("Stopped");
     }