Bug 9196 - authorities editor overlapping box

Bug 9196 - authorities editor overlapping box

This patch corrects a display problem in the authorities editor which
can cause the contents of a tab to overflow outside the tab's boundary.

To test open an authority record for editing. Confirm that tab contents
do not overflow their bounds on both tabs with many lines and tabs with
just one or two.

Signed-off-by: Pierre Angot <tredok.pierre@mail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>