Bug 36844: (QA follow-up) Fix preselected options on set-library.pl

Bug 36844: (QA follow-up) Fix preselected options on set-library.pl

I found that when switching from a branch with a default register to one without, the default register for
the last branch was remaining selected (though disabled)

When opening the page if no desk was set (choose 'My library' on initial login) the branch was default to 'No desk' rather than defaulting to the first desk of the current branch

Remove a debugging line as well

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>