Show language selector toggle always checked

[Kakifrucht]

Bug Report

Current Behavior
When multiple language packs are enabled the "Show language selector" toggle under basics is always checked, even if the feature has been disabled.

Steps to Reproduce

1. Enable multiple language packs.
2. Under basics, disable "Show language selector" setting.
3. The language selector won't be shown in the forum anymore as expected, but after reloading the admin page the toggle will be checked.

Expected Behavior
When the feature is disabled the selector shouldn't be checked on site load.

Environment

• Flarum version: 0.1.0-beta.15
• Webserver: nginx
• Hosting environment: root
• PHP version: 7.4.13