Sorting or moving of pages should be disabled if "Show content in [lang] only" is enabled

Description

Steps to reproduce:
1. Check "Show content in Svenska only", or any other non-master language of your site.
2. Try dragging pages under the start page for sorting.

Expected:
Sorting or moving of pages should be disabled if "show content in [lang] only" is enabled

Actual:
Dragged pages can be dropped in unexpected locations. This does not happen if the master language pages are showing as well.