Don't change combobox on mouse scroll

This causes problems and is inconvenient, easy to change
something by accident

fixes QubesOS/qubes-issues#9675

Author: marmarta

qubes_config/global_config/global_config.py

@@ -438,6 +438,12 @@ def perform_setup(self):
              self.builder.get_object('thisdevice_scrolled_window'),
              ])
 
+        # workaround the uncomfortable behavior with comboboxes: combobox
+        # should not change item ID on random scrolling around
+        for obj in self.builder.get_objects():
+            if isinstance(obj, (Gtk.ComboBox, Gtk.ComboBoxText)):
+                obj.connect('scroll-event', lambda *args: True)
+
         self.progress_bar_dialog.update_progress(1)
         self.progress_bar_dialog.hide()
         self.progress_bar_dialog.destroy()