This fixes showing "0% charging" on a desktop computer which has a
wireless mouse/keyboard. If there is no battery whatsoever it continues
to show "No batteries available" but for the aforementioned case the
generic "Battery and brightness" is shown in order not to lie to the user :)

CHANGELOG: Battery tooltip no longer shows "0% charging" for computers with wireless mouse/keyboard

BUG: 362924
Reviewed-By: mgraesslin