[pkg] Use Twisted < 16.0.0
We have some test failures with 16.0.0, such as:
- test_put_content (unittest_server.ETwistHTTPTC)
- test_base_url (unittest_httptest.TwistedCWAnonTC)
(grafted from 10c12f31d0fe38c2e8814176fc42bf2ea210efdf)
from os import unlink
from os.path import isfile, join
from cubicweb.cwconfig import CubicWebConfiguration as cwcfg
regdir = cwcfg.instances_dir()
if isfile(join(regdir, 'startorder')):
if confirm('The startorder file is not used anymore in Cubicweb 3.22. '
'Should I delete it?',
shell=False, pdb=False):
unlink(join(regdir, 'startorder'))