MediaWiki theme: Fix visual glitch CheckboxInputWidget's `:active` state
MediaWiki theme: Fix visual glitch CheckboxInputWidget's `:active` state

Fixing visual glitch in CheckboxInputWidget's `:active` state when
unchecked. Follow-up to Id29445aa9ad976c09832d660e7a7f0bcbf4cbb67

Change-Id: Ic7f2c990d4c7d8600d5328c7c48295ec6cf709ad

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui