fix syntax: err_count += 1
fix syntax: err_count += 1

https://stackoverflow.com/questions/2632677/python-integer-incrementing-with

henningjp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp