make glossary edit categories a little taller

Change-Id: Id5625b94bef8f580f3d895d302b4e1af18c0ed38
SvxMultiFileDialog is never created

because the single caller of it is a hidden button
in the old mail merge dialog which was never completed
to allow attachments to emails (because it never was
able to send emails, the new one can FWIW)

all of which has logical knock on effects to shrink
things down substantially

Change-Id: I831cac8f670eaafc96b2ea4d78516f67b662fa7d