[server] refactor server.utils.manager_userpasswd - remove passwd parameter which was never used - make the function usable when we have a login and want the user to enter a new password, with confirmation

"""pre 3.2 bw compat"""
# pylint: disable-msg=W0614,W0401
from warnings import warn
warn('moved to cubicweb.appobject', DeprecationWarning, stacklevel=2)
from cubicweb.appobject import *