Fix: resolve CLI auto-completion issue of openstack apps

Change-Id: I0dc973628910cae3588f25e066e81a87a4264f06
diff --git a/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java b/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java
index e2d37f7..17db27c 100644
--- a/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java
+++ b/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/cli/OpenstackVtapDeleteCommand.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.openstackvtap.cli;
 import org.apache.karaf.shell.api.action.Command;
+import org.apache.karaf.shell.api.action.Completion;
 import org.apache.karaf.shell.api.action.lifecycle.Service;
 import org.onosproject.cli.AbstractShellCommand;
 import org.apache.karaf.shell.api.action.Argument;
@@ -34,6 +35,7 @@
 
     @Argument(index = 0, name = "id", description = "vtap ID",
             required = true, multiValued = false)
+    @Completion(VtapIdCompleter.class)
     String vtapId = "";
 
     @Override