Fix empty statement in DidlBuilder.cs

Emby.Dlna/Didl/DidlBuilder.cs

@@ -932,7 +932,7 @@ namespace Emby.Dlna.Didl
 
         private void AddCover(BaseItem item, BaseItem context, StubType? stubType, XmlWriter writer)
         {
-            ImageDownloadInfo imageInfo = GetImageInfo(item);;
+            ImageDownloadInfo imageInfo = GetImageInfo(item);
 
             if (imageInfo == null)
             {