Interface changes to Catalan if system language is not in list
Steps to reproduce:
- Delete or rename mkvtoolnix-gui.ini
- Change system language to English (United Kingdom)
- Open MKVToolNix GUI and go to the settings
- Change any setting and press OK
The language changes to Catalan.
It seems like the language dropdown is set to Catalan when the dialog is opened, presumably because UK English is not in the list and Catalan is the first entry. But in that case, the dropdown should be set to English to match the interface.