Remove unused using

MediaBrowser.Api/DisplayPreferencesService.cs

@@ -6,7 +6,6 @@ using MediaBrowser.Controller;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Net;
 using MediaBrowser.Model.Entities;
-using MediaBrowser.Model.Querying;
 using MediaBrowser.Model.Services;
 using Microsoft.Extensions.Logging;