Fixed race condition in account update

        """ Update the database with accounts.

        """

        db_accounts = set((obj['a'].value for obj in self.db.objects if 'a' in obj))

        db_accounts = set((obj['a'].value for obj in list(self.db.objects) if 'a' in obj))

        accounts = set(self.conf.list_accounts())

        to_register = accounts - db_accounts