Delete sandbox on capsule delete

We need to delete the sandbox for cleaning up the networking
resources. Otherwise, the neutron ports of the capsule won't
be cleaned up.

Closes-Bug: #1762895
Change-Id: I798d32d04b679b4c3cfb48adbc21dade102b8ce3

zun/compute/manager.py

@@ -1155,6 +1155,7 @@ class Manager(periodic_task.PeriodicTasks):
                 container = \
                     objects.Container.get_by_uuid(context,
                                                   capsule.containers_uuids[0])
+                self._delete_sandbox(context, container, reraise=False)
                 self.container_delete(context, container, force=True)
         except Exception as e:
             LOG.exception(e)