Fixed #12468 -- Use the DatabaseOperations class from the `postgres…

…ql_psycopg2` backend as the base class for `PostGISOperations`. Thanks, drdaeman, for bug report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12033 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/db/backends/postgis/operations.py

@@ -8,8 +8,7 @@
 from django.contrib.gis.geometry.backend import Geometry
 from django.contrib.gis.measure import Distance
 from django.core.exceptions import ImproperlyConfigured
-from django.db.backends.postgresql.operations import DatabaseOperations
-from django.db.backends.postgresql_psycopg2.base import Database
+from django.db.backends.postgresql_psycopg2.base import Database, DatabaseOperations
 
 #### Classes used in constructing PostGIS spatial SQL ####
 class PostGISOperator(SpatialOperation):