Remove unused pubsub stuff

appengine/gce-backend/instances.py

 # Copyright 2016 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Utilities for operating on instances."""
 
 import json
 import logging
 
 from google.appengine.ext import ndb
 
 from components import gce
 from components import net
-from components import pubsub
 from components import utils
 
 import instance_group_managers
 import metrics
 import models
 import utilities
 
 
 def get_instance_key(base_name, revision, zone, instance_name):
   """Returns a key for an Instance.
@@ skipping 370 matching lines @@
   orphaned = 0
   for instance in models.Instance.query():
     total += 1
     instance_group_manager = instance.key.parent().get()
     if (not instance_group_manager
         or instance.key not in instance_group_manager.instances):
       logging.warning('Found orphaned Instance: %s', instance.key)
       orphaned += 1
   logging.info('Orphaned Instances: %s/%s', orphaned, total)
   return orphaned, total