return empty array for api/qvitter/mutes.json queries instead of html

lib/pleroma/web/router.ex

@@ -269,6 +269,7 @@ defmodule Pleroma.Web.Router do
     get("/friendships/no_retweets/ids", TwitterAPI.Controller, :empty_array)
 
     get("/mutes/users/ids", TwitterAPI.Controller, :empty_array)
+    get("/qvitter/mutes.json", TwitterAPI.Controller, :empty_array)
 
     get("/externalprofile/show", TwitterAPI.Controller, :external_profile)
   end