calcurse-upgrade: use $XDG_CONFIG_HOME
calcurse-upgrade: use $XDG_CONFIG_HOME

Signed-off-by: Lukas Fleischer <c9ca73f8336dcfb037ec2c2abf52d80a6847a5cd@calcurse.org>

lfos/calcurse,lfos/calcurse,lfos/calcurse