[test rql completion] dont limit number of completion, else we've impredicable results. Also should tell rql.parse to not print error on stdout This repairs test introduced by dcd9bc1d1bca which closes #2439846

# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s specific hooks and operations"""