ZUGFeRDService: Add Custom.RejectionTransferEnabled option

Services.ZUGFeRDService/ThreadRunner.vb

@@ -182,7 +182,9 @@ Public Class ThreadRunner
 
     Private Sub DoWork(sender As Object, e As DoWorkEventArgs) Handles _workerThread.DoWork
         Try
-            MaybeUpdateRejected()
+            If _config.Config.Custom.RejectionTransferEnabled = True Then
+                MaybeUpdateRejected()
+            End If
 
             Dim oArgs As WorkerArgs = e.Argument
             _logger.Debug("Background worker running..")