- fix a crash in checkboxtree.c where pressing pgup/pgdown   on a checkboxtree with less items than its height would   cause segmentation violation (#165347)
- fix a crash in checkboxtree.c where pressing pgup/pgdown
  on a checkboxtree with less items than its height would
  cause segmentation violation (#165347)

Distrotech/newt,Distrotech/newt,Distrotech/newt