Describe the bug
When cloning an event, the settings for "Default language", "Enforce language" and "Additional languages" are not cloned to the new event.

The source event had the settings set to English (US), Yes and English (UK), respectively. A clone of this event was successfully created with title, description etc., but the language settings were reset to no language preferences and "enforce language" set to no. As far as I can tell, none of the contents options should affect these settings.

To Reproduce
Steps to reproduce the behavior:

1. Go to "Settings" of an event with default language and enforce language set.
2. Click on 'Clone'
3. Select clone once, and proceed to creating the clone.
4. The cloned event does not have the same language settings.

Expected behavior
Language settings are cloned to the new event.

Additional context
Tested this on our local install of Indico v3.3.6.