Removed 2 DB queries per request when user is authenticated

api/funkwhale_api/users/auth_backends.py

@@ -0,0 +1,17 @@
+from django.contrib.auth import backends, get_user_model
+
+
+class ModelBackend(backends.ModelBackend):
+    def get_user(self, user_id):
+        """
+        Select related to avoid two additional queries
+        """
+        try:
+            user = (
+                get_user_model()
+                ._default_manager.select_related("actor__domain")
+                .get(pk=user_id)
+            )
+        except get_user_model().DoesNotExist:
+            return None
+        return user if self.user_can_authenticate(user) else None