This issue was identified upstream in https://bugs.launchpad.net/tripleo/+bug/1784233 and fixed in https://review.openstack.org/#/c/586904/. You need to rebase on kolla upstream, or cherry-pick https://review.openstack.org/#/c/586904/ downstream.
Can you cherry-pick this change?
Horizon containerized in: python-django-horizon-14.0.1-0.20181006183341.19865ee.el7ost.noarch
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/RHEA-2019:0048