new port: security/rubygem-omniauth-multipassword

Ruby gem that implements an OmniAuth strategy that allows to
authenticate against different password strategies at once.

WWW: https://github.com/jgraichen/omniauth-multipassword

PR: 199755
Differential Revision: https://reviews.freebsd.org/D2504
Submitted by: Torsten Zuehlsdorff <ports@toco-domains.de>
Approved by: mat (mentor)