"invalid URL" error should not trigger retry

[Alereon]

Summary: If uTorrent encounters an invalid URL error when attempting to contact a tracker, it will periodically retry in the same way that it does for other errors.

Steps to Reproduce:

1. Add any torrent containing an invalid tracker URL to uTorrent. An example is torrents from The Pirate Bay, which uses UDP trackers.

Actual Results: uTorrent retries the connection at the same rate it does for other errors.

Expected Results: As this is a fatal error for this tracker (an invalid tracker URL can never become valid unless support for it is added in a program update or the tracker URL is edited), uTorrent should not retry.

This clearly isn't a big deal, but maybe something to fix if the developers have time.