Autosave stops working when Language gadget is added

Description

Autosaving stops working on TinyMce properties if the Language Gadget is added.

When typing in the XHTML-property, after the first autosave occurs, if you stop for a couple of seconds, the autosave no longer saves. If you publish the page, all changes beyond the first save are gone. However, if you click outside the property and back inside, autosave starts working again.

Steps to reproduce:
1. Install Alloy site.
2. Install the Episerver.Labs.LanguageManager nuget package.
3. Activate another language on the Alloy site.
4. Add the Language gadget to the left pane.
5. Find a page with a XHTMLString property.
6. Go to "All properties".
7. Type a short text in the XHTMLString property.
8. Wait until the first autosave is complete.
9. Type some more. The autosave does not trigger.