Remove one remaining "differential.anonymous-access"

Fixes T4091.

Auditors: btrahan

Author: epriestley

conf/default.conf.php

@@ -855,11 +855,6 @@
   // not actually be receiving thorough review.
   'differential.enable-email-accept' => false,
 
-  // If you set this to true, users won't need to login to view differential
-  // revisions.  Anonymous users will have read-only access and won't be able to
-  // interact with the revisions.
-  'differential.anonymous-access' => false,
-
   // List of file regexps that should be treated as if they are generated by
   // an automatic process, and thus get hidden by default in differential.
   'differential.generated-paths' => array(