[py3] Fixed iterlists usage in QueryDict

    def __copy__(self):

        result = self.__class__('', mutable=True, encoding=self.encoding)

        for key, value in self.iterlists():

        for key, value in six.iterlists(self):

            result.setlist(key, value)

        return result

    def __deepcopy__(self, memo):

        result = self.__class__('', mutable=True, encoding=self.encoding)

        memo[id(self)] = result

        for key, value in self.iterlists():

        for key, value in six.iterlists(self):

            result.setlist(copy.deepcopy(key, memo), copy.deepcopy(value, memo))

        return result