FIX: add ReadOnly hear to /srv/status

spec/requests/forums_controller_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe ForumsController do
+
+  describe "read only header" do
+    it "returns no read only header by default" do
+      get "/srv/status"
+      expect(response.status).to eq(200)
+      expect(response.headers['Discourse-Readonly']).to eq(nil)
+    end
+
+    it "returns a readonly header if the site is read only" do
+      Discourse.received_readonly!
+      get "/srv/status"
+      expect(response.status).to eq(200)
+      expect(response.headers['Discourse-Readonly']).to eq('true')
+    end
+  end
+
+end