Make update_db an opt arg in scheduler manager.

Updates the scheduler manager so that update_db is an optional
argument. This fixes issues when trying to make RPC calls
with the most recent version (1.4) of the scheduler RPC API.

Fixes LP Bug #1035004.

Change-Id: Ib998c0465cead1b8e117a7344557f8ff496c7e40

nova/scheduler/manager.py

@@ -144,8 +144,8 @@ def run_instance(self, context, request_spec, admin_password,
 
     # FIXME(comstud): Remove 'update_db' in a future version.  It's only
     # here for rpcapi backwards compatibility.
-    def prep_resize(self, context, image, update_db, request_spec,
-                    filter_properties, instance=None, instance_uuid=None,
+    def prep_resize(self, context, image, request_spec, filter_properties,
+                    update_db=None, instance=None, instance_uuid=None,
                     instance_type=None, instance_type_id=None, topic=None):
         """Tries to call schedule_prep_resize on the driver.
         Sets instance vm_state to ACTIVE on NoHostFound