Apply flair prefs to cache keys, even for UnloggedUser.

This is necessary because comment rendering makes a pass using
UnloggedUser, but needs to preserve the actual signed-in user's
preferences.

r2/r2/lib/wrapped.pyx

@@ -461,7 +461,7 @@ class CachedTemplate(Templated):
                 template_hash, g.markdown_backend]
 
         # if viewing a single subreddit, take flair settings into account.
-        if c.user_is_loggedin and hasattr(c.site, '_id'):
+        if c.user and hasattr(c.site, '_id'):
             keys.extend([
                 c.site.flair_enabled, c.site.flair_position,
                 c.user.flair_enabled_in_sr(c.site._id),