0320+0321: redundant prefs, closes #793

user.js

@@ -209,10 +209,7 @@ user_pref("dom.ipc.plugins.flash.subprocess.crashreporter.enabled", false);
 user_pref("dom.ipc.plugins.reportCrashURL", false);
 /* 0320: disable about:addons' Recommendations pane (uses Google Analytics) ***/
 user_pref("extensions.getAddons.showPane", false); // [HIDDEN PREF]
-user_pref("extensions.webservice.discoverURL", "");
 /* 0321: disable recommendations in about:addons' Extensions and Themes panes [FF68+] ***/
-user_pref("extensions.getAddons.discovery.api_url", "");
-user_pref("extensions.htmlaboutaddons.discover.enabled", false);
 user_pref("extensions.htmlaboutaddons.recommendations.enabled", false);
 /* 0330: disable telemetry
  * the pref (.unified) affects the behaviour of the pref (.enabled)