[ibr-dtn] Patch: dtnping

To whom it might concern,

while I was playing around with dtnping I found out, that you are not able to close dtnping in case you called it with the option --nowait. Neither helped CTRL+C nor a kill command.

I looked at the code for the case without --nowait, and found a helping piece for the --nowait case. Now you are able to interrupt dtnping even if you called it with --nowait.

Hope my solution, which is in the attachment, is okay.

With best regards,

Kevin Baron