Issue 4577 - Remove Safari support

lib/prefs.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 159 matching lines @@
 /**
  * Additonal subscriptions to be automatically added when the extension is
  * loaded. This preference isn't set by the extension but can be pre-configured
  * externally.
  *
  * @type {string[]}
  */
 defaults.additional_subscriptions = [];
 
 /**
- * Whether to enable the use of Safari's content blocker mechanism.
- */
-defaults.safariContentBlocker = false;
-
-/**
   * @namespace
   * @static
   */
 let Prefs = exports.Prefs = {
   /**
    * Adds a callback that is called when the
    * value of a specified preference changed.
    *
    * @param {string}   preference
    * @param {function} callback
@@ skipping 122 matching lines @@
           eventEmitter.emit(pref);
         }
       }
     });
   }
 
   Prefs.untilLoaded = Promise.all([localLoaded, managedLoaded]).then(onLoaded);
 }
 
 init();