Fixes possible charge issues in the future (#65309)
Fixes possible charge issues in the future (#65309)

Replaced if(!parameter) checks with if(!isnull(parameter)). Right now you can't set destroy_objects to FALSE using the destroy argument in New() because the game will think value wasn't changed.
Fixed actively_moving being TRUE after first charge.

This PR will prevent tarantulas and other mobs that can charge from moving and destroying stuff during charge delay.
Also this PR will let us avoid problems in the future if someone decides to override destroy_objects in New()
Jordie0608/tgstation,MicroWorldwide/SS13-TG-station,Cruix/-tg-station,MicroWorldwide/SS13-TG-station,Jordie0608/tgstation,ShizCalev/tgstation,tgstation/-tg-station,Jordie0608/tgstation,MicroWorldwide/SS13-TG-station,Bawhoppen/-tg-station,tgstation/-tg-station,ShizCalev/tgstation,Cruix/-tg-station,Cruix/-tg-station,Bawhoppen/-tg-station,CPTANT/-tg-station,Cruix/-tg-station,ShizCalev/tgstation,CPTANT/-tg-station,tgstation/tgstation,CPTANT/-tg-station,Bawhoppen/-tg-station,Cruix/-tg-station,CPTANT/-tg-station,CPTANT/-tg-station,tgstation/-tg-station,tgstation/tgstation,Jordie0608/tgstation,CPTANT/-tg-station,tgstation/tgstation,tgstation/tgstation,tgstation/tgstation,ShizCalev/tgstation,MicroWorldwide/SS13-TG-station,Cruix/-tg-station,tgstation/-tg-station,CPTANT/-tg-station,Bawhoppen/-tg-station,tgstation/tgstation,MicroWorldwide/SS13-TG-station,Bawhoppen/-tg-station,ShizCalev/tgstation,MicroWorldwide/SS13-TG-station,Jordie0608/tgstation,Bawhoppen/-tg-station,CPTANT/-tg-station,MicroWorldwide/SS13-TG-station,ShizCalev/tgstation,Cruix/-tg-station,tgstation/tgstation,MicroWorldwide/SS13-TG-station,Bawhoppen/-tg-station,ShizCalev/tgstation,Jordie0608/tgstation,Jordie0608/tgstation,ShizCalev/tgstation,Jordie0608/tgstation,tgstation/tgstation,Bawhoppen/-tg-station,Cruix/-tg-station