D8980: Fix rubber band selection drawing contents misaligned with scaling

[David Edmundson]

davidedmundson marked an inline comment as done.

REPOSITORY
  R223 Okular

REVISION DETAIL
  https://phabricator.kde.org/D8980

To: davidedmundson, aacid
Cc: sander, rkflx, anthonyfieroni, #okular, michaelweghorn, ngraham, aacid