See
https://gitlab.com/gitlab-org/gitlab-ee/commit/4b5a1c9a6570d70cd3e16b3c1d3c2ec0471f46eb#777d5694836def44d2a73f1c7590aea20aed6c22_35_35
From MR: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1797/
Since .panel-heading is a bit different from bootstrap, using .panel-title for h3 looks different.
So with this .panel-title will look good again inheriting custom properties our app sets for .panel-heading