[bug] Power applet display brightness percentage is off by one

[alphabitserial]

Cosmic-applets version: 1.0.0.alpha.1.r37.g0a32d27-1

Specific applet that this is regarding (if applicable): Power

Issue/Bug description: The percentage displayed next to the power applet's display brightness is off by +1

Steps to reproduce: Observe that the OSD while changing brightness does not always match the value in the power applet. At 0% display brightness, the value will read 1%.

Expected behavior: The value should match the actual display brightness.

Other notes: See the attached screenshot