Remove possible division by 0, closes #1270 (#1271)
Remove possible division by 0, closes #1270 (#1271)

* Remove possible division by 0, closes #1270

dcprojects/CoolProp,JonWel/CoolProp,dcprojects/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,DANA-Laboratory/CoolProp,JonWel/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,JonWel/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,henningjp/CoolProp,JonWel/CoolProp,dcprojects/CoolProp,henningjp/CoolProp,dcprojects/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,DANA-Laboratory/CoolProp,JonWel/CoolProp,dcprojects/CoolProp,JonWel/CoolProp,CoolProp/CoolProp,dcprojects/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,JonWel/CoolProp,dcprojects/CoolProp,henningjp/CoolProp,henningjp/CoolProp