security/py-fail2ban: Fix rc script

The rc.d script evaluates fail2ban_pidfile before rc.conf is read.

This change moves those evaluations to the corect place allowing
users to override the values via /etc/rc.conf as expected.

PR: 236017
Reported by: <epopen gmail com>, Dmitry Wagin <dmitry.wagin ya ru>
Submitted by: <theis gmx at> (maintainer)
MFH: 2019Q2