Okular multipage option doesn't work with pdf printer

[Andrea]

When printing from Okular with the pdf printer ("print to file (PDF)"), the multipage option is ineffective.
The resulting pdf is the same than the original.

Description: Ubuntu 16.04.1 LTS
Release: 16.04

okular:
  Installato: 4:16.04.3-0ubuntu1~ubuntu16.04~ppa50
  Candidato: 4:16.04.3-0ubuntu1~ubuntu16.04~ppa50
  Tabella versione:
 *** 4:16.04.3-0ubuntu1~ubuntu16.04~ppa50 500
        500 http://ppa.launchpad.net/kubuntu-ppa/backports-landing/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status
     4:15.12.3-0ubuntu1 500
        500 http://it.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages