Cycles: Fix after recent merge from master

random_id() crashes when there is no current dupli object.

We could also throw a Python error when doing it via RNA, but as far as
Cycles is concerned we need to check if instanced.

intern/cycles/blender/blender_object.cpp

@@ -295,7 +295,7 @@ Object *BlenderSync::sync_object(BL::Depsgraph::duplis_iterator& b_dupli_iter,
 			           persistent_id,
 			           b_ob,
 			           b_ob_instance,
-			           b_dupli_iter->random_id(),
+			           is_instance ? b_dupli_iter->random_id() : 0,
 			           tfm,
 			           use_portal);
 		}