Look for nested if statements with relatively small conditions, where
they can be collapsed into one if statement.

Change-Id: I7d5d4e418d0ce928991a3308fc88969c00c0d0f2
Reviewed-on: https://gerrit.libreoffice.org/62898
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>