Fix import of rooms for extra lessons

aleksis/apps/untis/util/mysql/importers/substitutions.py

@@ -193,7 +193,6 @@ def import_substitutions(
 
                 groups = [classes_ref[pk] for pk in untis_split_first(sub.classids, int)]
 
-                rooms = rooms_old if not room_new and rooms_old else [room_new]
                 subject = subject_new if subject_new else subject_old
                 if not teacher_new and not teacher_old:
                     teachers = []