Use moved manage.py in horizion

Change-Id: Idb769634fd7d7fc4efce974690b5f24cf632d83d
diff --git a/stack.sh b/stack.sh
index e1b005e..3ecfc78 100755
--- a/stack.sh
+++ b/stack.sh
@@ -709,7 +709,7 @@
     # Initialize the horizon database (it stores sessions and notices shown to
     # users).  The user system is external (keystone).
     cd $HORIZON_DIR/openstack-dashboard
-    dashboard/manage.py syncdb
+    python manage.py syncdb
 
     # create an empty directory that apache uses as docroot
     sudo mkdir -p $HORIZON_DIR/.blackhole