auth/pycreds/encrypt_netr_crypt_password: don't pretend arg is optional

auth/pycreds/encrypt_netr_crypt_password: don't pretend arg is optional

The "|O" signature is saying the password argument is optional, which
makes no sense in terms of the funxtion and immediately leads to a
TypeError (or until last commit, segfault). Removing the "|" leaves it
with a TypeError, but it is better worded and faster.

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>