[Python 3] fork code harmonizing

Summary:
fixes error in Python3 running saslauthd.py in fork mode

Code harmonized with code in def run of kolabd/__init.py and wallace/init__.py

Reviewers: PyKolab Developers, sicherha

Reviewed By: PyKolab Developers, sicherha

Subscribers: sicherha

Differential Revision: https://git.kolab.org/D3442