The `gcal_agenda_view_first_weekday_changed` uses the same
`gtk_list_view_scroll_to` method that expects the scroll position to be
smaller than the number of items in the list model.
When the list model contains no items, the method reports a critical
which crashes the Calendar whith `fatal-criticals` enabled.
This is the same fix that Georges made in the
`gcal_agenda_view_set_date` method. We now check the number of items
before trying to scroll the list view to position zero.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/861>
mindonwarp
0a72c05311