Don't pop from empty step list, this fixes #55
Don't pop from empty step list, this fixes #55

If the user didn't add any repetitions to the workout, the timer isn't
very useful anyway, so just ignoring this is OK.

wger-project/wger,DeveloperMal/wger,wger-project/wger,rolandgeider/wger,rolandgeider/wger,petervanderdoes/wger,DeveloperMal/wger,petervanderdoes/wger,DeveloperMal/wger,wger-project/wger,rolandgeider/wger,kjagoo/wger_stark,kjagoo/wger_stark,wger-project/wger,kjagoo/wger_stark,petervanderdoes/wger,kjagoo/wger_stark,DeveloperMal/wger,rolandgeider/wger,petervanderdoes/wger