Remove unused last-modified check from GET_stylesheet.

We no longer write to the old last modified system for stylesheets
anyway, so there's no point in checking.  S3 handles last modified for
the staticized stylesheets anyway.

r2/r2/controllers/front.py

@@ -401,9 +401,6 @@ class FrontController(RedditController, OAuth2ResourceController):
 
         if stylesheet_contents:
             c.allow_loggedin_cache = True
-            self.check_modified(c.site,'stylesheet_contents',
-                                private=False, max_age=7*24*60*60,
-                                must_revalidate=False)
             c.response_content_type = 'text/css'
             c.response.content =  stylesheet_contents
             if c.site.type == 'private':