Reduce number of translatable strings in columnpage.ui

Change-Id: Id3d8744bed8ac8366b10f93fa8e38803316eeb82
Reviewed-on: https://gerrit.libreoffice.org/46171Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>