Import FieldDoesNotExist from the correct place

python/nav/django/utils.py

@@ -16,7 +16,7 @@
 #
 
 """Utility methods for django used in NAV"""
-from django.db.models.fields import FieldDoesNotExist
+from django.core.exceptions import FieldDoesNotExist
 from django.urls import reverse
 from django.utils.http import urlencode
 

python/nav/web/api/v1/views.py

@@ -22,7 +22,7 @@
 from django.http import HttpResponse, JsonResponse
 from django.db.models import Q
 from django.db.models.fields.related import ManyToOneRel as _RelatedObject
-from django.db.models.fields import FieldDoesNotExist
+from django.core.exceptions import FieldDoesNotExist
 import iso8601
 
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet

python/nav/web/seeddb/utils/list.py

@@ -21,7 +21,7 @@
 
 from django.db.models import Model
 from django.shortcuts import render
-from django.db.models.fields import FieldDoesNotExist
+from django.core.exceptions import FieldDoesNotExist
 from django.urls import reverse
 from six import iteritems