FIELD_HISTORY_OBJECT_ID_TYPE not working with django-configurations

[sreyemnayr]

I'm not certain if this was exclusive to django-configurations, but setting FIELD_HISTORY_OBJECT_ID_TYPE = models.IntegerField caused it to error out because an instance of the class was being passed, not the class itself. This hotfix checks to see if that's what's being passed first and converts it back to the class if that's the case.

[coveralls]

Coverage decreased (-0.3%) to 95.057% when pulling bfd3308e3dd35c144e383802528fa4fb94ccd103 on sreyemnayr:master into b61885d8bddf7d1f53addf3bea098f67fcf9a618 on grantmcconnaughey:master.