Fixes a runtime with map voting (#69908)
Fixes a runtime with map voting (#69908)

* Adds a sanity check in voting, in case no one actually voted.
ShizCalev/tgstation,tgstation/tgstation,Bawhoppen/-tg-station,tgstation/tgstation,Bawhoppen/-tg-station,Bawhoppen/-tg-station,Bawhoppen/-tg-station,ShizCalev/tgstation,tgstation/tgstation,Bawhoppen/-tg-station,Bawhoppen/-tg-station,ShizCalev/tgstation,tgstation/tgstation,Bawhoppen/-tg-station,tgstation/tgstation,ShizCalev/tgstation,tgstation/tgstation,Bawhoppen/-tg-station,ShizCalev/tgstation,tgstation/tgstation,ShizCalev/tgstation,tgstation/tgstation,ShizCalev/tgstation,ShizCalev/tgstation