Hi, I wanna to enable prometheus metrics for gitlab. So I add `gitlab_rails['env'] = { 'prometheus_multiproc_dir' => '/dev/shm' }` into my `gitlab.rb` And than select the checkbox, restart my gitlab like thie image:  But I still can't visit the metrics page through url: ``` http://git.foobar.com/-/metrics?token=cXaSVqabTgDFvJgwV6Uz ``` Response message list this: ``` # Metrics are disabled, see: http://git.foobar.com/help/administration/monitoring/prometheus/gitlab_metrics#gitlab-prometheus-metrics ``` Have I config something wrong? Thank you very mach.