Meta topic: https://meta.discourse.org/t/reseting-robots-txt-override-doesnt-seem-to-work-as-expected/287880?u=osama
Discourse provides a default version for `/robots.txt` which can be customized by admins in `/admin/customize/robots`. In that page, there's a button to reset back to the default version that Discourse provides. However, there's currently a bug with the reset button where the content appears to change to some HTML document instead of the default `robots.txt` version when clicking the button. Refreshing the page shows the true/correct content of `robots.txt` which is the default version, so the reset button actually works but there's a display problem.
What causes this display problem is that we use Rails' `render_to_string` method to generate the default content for `robots.txt` from the template, and what we get from that method is the `robots.txt` content wrapped in the application layout. To fix this issue, we need to pass `layout: false` to the `render_to_string` method so that it renders the template without any layouts.
* FEATURE: Allow customization of robots.txt
This allows admins to customize/override the content of the robots.txt
file at /admin/customize/robots. That page is not linked to anywhere in
the UI -- admins have to manually type the URL to access that page.
* use Ember.computed.not
* Jeff feedback
* Feedback
* Remove unused import
