'Ask the user if he wants to update or not.
:return: True if the user wants to update.'

def _user_confirmed_update(self, short_local_head_id, local_head_id, short_remote_head_id, remote_head_id):

    if (self.callback_onupdate_confirm is not None):
        callback = self.callback_onupdate_confirm
        msg = 'Your    current    w3af    installation    is    %s    (%s).    Do    you    want    to    update    to    %s    (%s)?'
        proceed_upd = callback((msg % (short_local_head_id, get_commit_id_date(local_head_id), short_remote_head_id, get_commit_id_date(remote_head_id))))
        return proceed_upd
