Changing the thumbnail ordering in a project with no photos causes a crash

0. Start in debug mode.
1. Open a project with no photos.
2. Change "Sort by" from "image name" to "time of import" (or the other way round). Program crashes:

Traceback (most recent call last):
  File "D:\work\arthropods\arthropoddescriber2repository\arthropod_describer_py\maphis\app.py", line 526, in sort_by
    sel_index = self.image_list.selectedIndexes()[0]
IndexError: list index out of range

Process finished with exit code 1