delete_config <peer> <source>
        eg. delete_config sw1 startup

def do_delete_config(self, line):
        """delete_config <peer> <source>
        eg. delete_config sw1 startup
        """

        def f(p, args):
            try:
                source = args[0]
            except:
                print("argument error")
                return
            print(p.delete_config(source))

        self._request(line, f)