[1.5.x] Fixed #19824 - Corrected the class described for Field.primary_key from IntegerField to AutoField.
[1.5.x] Fixed #19824 - Corrected the class described for Field.primary_key from IntegerField to AutoField.

Thanks Keryn Knight.

Backport of 218bbef0c4 from master

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