Merge branch 'dev' of https://github.com/MediaBrowser/Emby into dev

MediaBrowser.Providers/TV/TvExternalIds.cs

@@ -88,7 +88,7 @@ namespace MediaBrowser.Providers.TV
 
         public string UrlFormatString
         {
-            get { return null; }
+            get { return "https://thetvdb.com/index.php?tab=episode&id={0}"; }
         }
 
         public bool Supports(IHasProviderIds item)