Merge branch '199701-rails-6-blocked-host-error-when-using-qa-tunnel' into 'master'

Add Gitlab.config.gitlab.host to development host whitelist

Closes #199701

See merge request gitlab-org/gitlab!24044

config/initializers/rails_host_authorization.rb

+# frozen_string_literal: true
+
+# This file requires config/initializers/1_settings.rb
+
+if Rails.env.development?
+  Rails.application.config.hosts << Gitlab.config.gitlab.host
+end