[1.5.x] Fixed #20525 -- Added versionadded for clearsessions.
[1.5.x] Fixed #20525 -- Added versionadded for clearsessions.

Thanks wiml@.

Backport of 8a6e040bfa from master

ccn-2m/django,bliti/django-nonrel-1.5,hasadna/django,bliti/django-nonrel-1.5,ccn-2m/django,imtapps/django-imt-fork,alx-eu/django,alx-eu/django,alx-eu/django,imtapps/django-imt-fork,ccn-2m/django,hasadna/django,ccn-2m/django,imtapps/django-imt-fork,hasadna/django,alx-eu/django,bliti/django-nonrel-1.5