less if-nesting in ThumnailView
less if-nesting in ThumnailView

Easier to read.

Change-Id: I1ceb551d8badffb211b1f444b61375a03cac1348
Signed-off-by: Rodolfo Ribeiro Gomes <16e015bd1ac6d822a87827be2c0b511db515eae9@gmail.com>
Reviewed-on: https://gerrit.libreoffice.org/6643
Reviewed-by: Noel Grandin <43cf663cd6d200b6fda42cd74c2a9550f05ea5d0@gmail.com>
Tested-by: Noel Grandin <43cf663cd6d200b6fda42cd74c2a9550f05ea5d0@gmail.com>

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core