Settings page checkboxes get stuck

Environment

• OS version: Ubuntu 20.04
• Browser version: Chrome 88
• Extension version: release-2020-1
• Last working version: TBD

Steps to reproduce

1. Open settings page.
2. Repeatedly click on "Block additional tracking" checkbox in quick succession.

Observed behavior

After a couple of clicks:

• The checkbox gets stuck at its "on" position and no longer responds to clicks.
• EasyPrivacy filter list is not installed.

Expected behavior

Event after many clicks, the checkbox remains interactive and always correctly reflects whether the EasyPrivacy filter list is active (i.e. installed and enabled).

Further information

Originally reported at trac#7176.