Removed unnecessary usings

Emby.Server.Implementations/ApplicationHost.cs

@@ -80,7 +80,6 @@ using MediaBrowser.Controller.Subtitles;
 using MediaBrowser.Controller.TV;
 using MediaBrowser.LocalMetadata.Savers;
 using MediaBrowser.MediaEncoding.BdInfo;
-using MediaBrowser.Model.Activity;
 using MediaBrowser.Model.Configuration;
 using MediaBrowser.Model.Cryptography;
 using MediaBrowser.Model.Dlna;
@@ -99,7 +98,6 @@ using MediaBrowser.Providers.Subtitles;
 using MediaBrowser.WebDashboard.Api;
 using MediaBrowser.XbmcMetadata.Providers;
 using Microsoft.AspNetCore.Http;
-using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Prometheus.DotNetRuntime;