Installed OSP8 with openstack-puppet-modules-7.1.5-7.el7ost from brew. Verified that it works and that the /etc/httpd/conf.d/15-horizon_vhost.conf file contains the line WSGIApplicationGroup %{GLOBAL}.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2017:3287