Comment 20 for bug 1573488

Queens still has such issue.

Env:
CentOS 7.2
kernel: 3.10.0-514.el7.x86_64
rpm -qa|grep dashboard
openstack-dashboard-13.0.1-1.el7.noarch

Install doc:
https://docs.openstack.org/horizon/queens/install/install-rdo.html

And yes, add the fix to /etc/httpd/conf.d/openstack-dashboard.conf
WSGIApplicationGroup %{GLOBAL}
then restart the httpd service:
systemctl restart httpd.service