Initialize RoboCommand object only when a transfer starts.

Currently there are no references to the object before a transfer has
started, so it is safe to only initialize it in the StartTransfer()
method.

ATxService/AutoTx.cs

@@ -189,11 +189,8 @@ namespace ATxService
         /// </summary>
         private void LoadSettings() {
             try {
-
                 LoadConfigXml();
                 LoadStatusXml();
-
-                _roboCommand = new RoboCommand();
             }
             catch (Exception ex) {
                 Log.Error("LoadSettings() failed: {0}\n{1}", ex.Message, ex.StackTrace);

ATxService/RoboCommand.cs

@@ -21,6 +21,7 @@ namespace ATxService
             if (_transferState != TxState.Stopped)
                 return;
 
+            _roboCommand = new RoboCommand();
             _status.CurrentTransferSrc = sourcePath;
             _status.CurrentTransferSize = FsUtils.GetDirectorySize(sourcePath);
 
@@ -163,7 +164,6 @@ namespace ATxService
             _txCurFileSize = 0;
             _txCurFileProgress = 0;
             _roboCommand.Dispose();
-            _roboCommand = new RoboCommand();
             _status.TransferInProgress = false;
         }