APC overlay bugfix.

Before: If you turned off the breaker and fiddled with on/off states and turned on the breaker it wouldn't update the overlay because the check_updates wasn't doing an if(operating) check and would think it didn't need to update the overlays once you turned on the breaker.

After: Check_update() is doing a check for the breaker being on or off and taking that into account with the update_overlay flags and will update the overlays properly.

Thanks Razharas from /tg/ #coderbus for bringing this to my attention.
Merge pull request #4532 from Ccomp5950/apc_breaker

APC overlay bugfix.