D8385: Set the columns in "Overview" mode to match the amount of pages if document is small

[Lex Dem]

lexdem added a comment.


  Week already passed? :) I just waiting to continue coding and still didn't 
ruin the workflow for this commit :)

REPOSITORY
  R223 Okular

REVISION DETAIL
  https://phabricator.kde.org/D8385

To: lexdem, #okular, rkflx, ngraham
Cc: ltoscano, aacid, rkflx, ngraham