security/py-fail2ban: Create required start dir

Reported at https://github.com/fail2ban/fail2ban/issues/2634
fail2ban should check and, if necessary create, the required directory.

It is still up to the user to ensure that configuration in fail2ban's
conf files and FreeBSD's /etc/rc.conf are in sync and that both, pidfile
and socket reside in the same directory.

PR: 244092
Approved by: maintainer
MFH: 2021Q2