python 3 fixes

quality fixes

openedx/core/djangoapps/api_admin/models.py

@@ -15,6 +15,8 @@ from django.dispatch import receiver
 from django.urls import reverse
 from django.utils.translation import ugettext as _u
 from django.utils.translation import ugettext_lazy as _
+from django.utils.encoding import python_2_unicode_compatible
+
 from model_utils.models import TimeStampedModel
 from six.moves.urllib.parse import urlunsplit  # pylint: disable=import-error
 
@@ -129,6 +131,7 @@ class ApiAccessRequest(TimeStampedModel):
         return u'ApiAccessRequest {website} [{status}]'.format(website=self.website, status=self.status)
 
 
+@python_2_unicode_compatible
 class ApiAccessConfig(ConfigurationModel):
     """
     Configuration for API management.
@@ -136,8 +139,8 @@ class ApiAccessConfig(ConfigurationModel):
     .. no_pii:
     """
 
-    def __unicode__(self):
-        return u'ApiAccessConfig [enabled={}]'.format(self.enabled)
+    def __str__(self):
+        return 'ApiAccessConfig [enabled={}]'.format(self.enabled)
 
 
 @receiver(post_save, sender=ApiAccessRequest, dispatch_uid="api_access_request_post_save_email")