LinGui: fix a problem with batch enqueue

The current chapter start/end was applied to all titles.  So if the
currently selected title has fewer chapters than other titles, chapters
would be missing in the encoded titles.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5449 b64f7644-9d1e-0410-96f1-a4d463321fa5