use synchronizers.openstack.openstacksyncstep instead of synchronizers.base.openstacksyncstep

Change-Id: I0e315695cb0b38ce56368721a0b4ea131ae339d4
diff --git a/xos/synchronizer/steps/sync_instances.py b/xos/synchronizer/steps/sync_instances.py
index 5cec50d..aa0a443 100644
--- a/xos/synchronizer/steps/sync_instances.py
+++ b/xos/synchronizer/steps/sync_instances.py
@@ -4,7 +4,7 @@
 from django.db.models import F, Q
 from xos.config import Config
 from xos.settings import RESTAPI_HOSTNAME, RESTAPI_PORT
-from synchronizers.base.openstacksyncstep import OpenStackSyncStep
+from synchronizers.openstack.openstacksyncstep import OpenStackSyncStep
 from core.models.instance import Instance
 from core.models.slice import Slice, SlicePrivilege, ControllerSlice
 from core.models.network import Network, NetworkSlice, ControllerNetwork