Add a message to try and stop Meta disabling

We're repeatedly getting threatened with removing access by Meta, I
think because we have an unusual approach. We've jumped through all
their hoops but they don't seem to be reading the instructions.

I doubt this will do anything, but it's worth a try.

app/controllers/sessions_controller.rb

@@ -33,8 +33,13 @@ def failure
 
   def unknown_facebook_id_message(user_id)
     "Your Facebook ID for #{tc('site_name')} (#{user_id}) isn't in the approved list.\n" \
+      "\n" \
       "If you've been invited to become an editor, " \
-      "please contact the main site admins and get them to add this ID"
+      "please contact the main site admins and get them to add this ID. \n" \
+      "\n" \
+      "IF YOU ARE A TESTER FROM META:\n" \
+      "Please read the testing instructions which we've written for you on the app dashboard! \n" \
+      "We've given you credentials for a test user - PLEASE USE THOSE AND STOP DISABLING OUR ACCESS!"
   end
 
   def login_session

app/views/shared/_flash.html.erb

@@ -1,3 +1,3 @@
 <% flash.each do |key, message| %>
-  <%= content_tag :div, message, class: key, data: { controller: "flash" } %>
+  <%= content_tag :div, simple_format(message), class: key, data: { controller: "flash" } %>
 <% end %>