Don't fail when a torrent not in the download list finishes.

Tribler/Main/tribler_main.py

@@ -695,15 +695,17 @@ def sesscb_ntfy_torrentupdates(self, events):
  torrent = t.torrent if isinstance(t, CollectedTorrent) else t
  self.frame.librarydetailspanel.setTorrent(torrent)
 
- def sesscb_ntfy_torrentfinished(self, subject, changeType, objectID, *args):
+ def sesscb_ntfy_torrentfinished(self, subject, changeType, infohash, *args):
  self.guiUtility.Notify(
  "Download Completed", "Torrent '%s' has finished downloading. Now seeding." %
  args[0], icon='seed')
 
  if self._frame_and_ready():
- infohash = objectID
  torrent = self.guiUtility.torrentsearch_manager.getTorrentByInfohash(infohash)
- self.guiUtility.library_manager.addDownloadState(torrent)
+ # Check if we got the actual torrent as the bandwith investor
+ # downloads aren't going to be there.
+ if torrent:
+ self.guiUtility.library_manager.addDownloadState(torrent)
 
  @forceWxThread
  def sesscb_ntfy_newversion(self, subject, changeType, objectID, *args):