You need also to add jessie-backports repos to your sources.list
deb http://ftp.debian.org/debian jessie-backports main
Than -apt-get update
apt-get -t jessie-backports install python-otr
apt-get install python-sipsimple
apt-get install sipclients
That's it :) All thanks goes to Saúl Ibarra Corretgé from AG Project.
