[odtn] Fix bug in order to delete lower-connections properly when connectivity deleted

Change-Id: Ib721746cd5040ec377e91aed3bde2ea21cbc5616
diff --git a/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiConnectionHandler.java b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiConnectionHandler.java
index 47bf1b2..e8e7ce2 100644
--- a/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiConnectionHandler.java
+++ b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiConnectionHandler.java
@@ -117,6 +117,7 @@
                     .map(id -> {
                         TapiConnectionHandler handler = new TapiConnectionHandler();
                         handler.setId(Uuid.fromString(id.toString()));
+                        handler.read();
                         return handler;
                     }).collect(Collectors.toList());
         } catch (NullPointerException e) {