Disable warning about unused class.

Duplicati/Library/Backend/Rclone/Rclone.cs

@@ -17,7 +17,7 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 // 
 #endregion
-using Duplicati.Library.Common.IO;
+using Duplicati.Library.Common.IO;
 using Duplicati.Library.Interface;
 using Duplicati.Library.Utility;
 using Newtonsoft.Json;
@@ -32,6 +32,8 @@ using System.Threading.Tasks;
 
 namespace Duplicati.Library.Backend
 {
+    // ReSharper disable once UnusedMember.Global
+    // This class is instantiated dynamically in the BackendLoader.
     public class Rclone : IBackend
     {
         private const string OPTION_LOCAL_REPO = "rclone-local-repository";