use the new django app loading system

gestioncof/csv_views.py

@@ -1,7 +1,7 @@
 import csv
 from django.http import HttpResponse, HttpResponseForbidden
 from django.template.defaultfilters import slugify
-from django.db.models.loading import get_model
+from django.apps import apps
 from django.contrib.auth.models import User
 
 def export(qs, fields=None):
@@ -38,7 +38,7 @@ def admin_list_export(request, model_name, app_label, queryset=None, fields=None
     if not request.user.is_staff:
         return HttpResponseForbidden()
     if not queryset:
-        model = get_model(app_label, model_name)
+        model = apps.get_model(app_label, model_name)
         queryset = model.objects.all()
         filters = dict()
         """