Bug 16013: Make classification sources deletable

Bug 16013: Make classification sources deletable

Because of a wrong variable scope, the classification sources are not
deletable.

Test plan:
Create a classification sources (admin/classsources.pl)
Try to delete it
Without this patch, the classification source won't be deleted
With this patch, it will work!

Signed-off-by: Srdjan <srdjan@catalyst.net.nz>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com
(cherry picked from commit f6463317db08b9a4218ad94a2d191a5f5216c8c5)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>