[test/web] fix invisibly bogus test (prepares #2755994)
The test was wrong but that was cancelled out by a cache effect and
fuzzy naming.
Wiping the entity caches restores sanity: the choices list are the
same before and after the SET.
Also field.choices uses entity.unrelated but always returns related +
unrelated elements.
Hence `choice` replaces `unrelated` where it makes sense.
AssertIn is used in place of AssertTrue.
from logilab.common.shellutils import generate_password
from cubicweb.server.utils import crypt_password
for user in rql('CWUser U WHERE U cw_source S, S name "system", U upassword P, U login L').entities():
salt = user.upassword.getvalue()
if crypt_password('', salt) == salt:
passwd = generate_password()
print 'setting random password for user %s' % user.login
user.set_attributes(upassword=passwd)
commit()