removed useless import

Author: daimor

django_iris/base.py

@@ -5,7 +5,6 @@
 from django.utils.asyncio import async_unsafe
 from django.utils.functional import cached_property
 from django.db.utils import DatabaseErrorWrapper
-from django.db.backends.utils import debug_transaction
 
 from .introspection import DatabaseIntrospection
 from .features import DatabaseFeatures