The simplest approach is to use the workaround command in this post in the original thread I linked to.
https://community.ipfire.org/t/log-summary-openvpn-no-crl-update/11816/5
That command will update the CRL using the new updated location for the ovpn.cnf file.
It will not fix the bug but it will renew the CRL for another month and by then Core Update 187 should be released, it is already out in Testing phase and would be expected to be released fully by end of July. That update has the bug fix in it and will ensure that the automatic update of the CRL occurs again.