contrib/caldav/README.md: Fix localhost URI
contrib/caldav/README.md: Fix localhost URI

Signed-off-by: Raf Czlonka <62837b5118cd753fc0514b84b9c13d1be107fc29@gmail.com>
Signed-off-by: Lukas Fleischer <c9ca73f8336dcfb037ec2c2abf52d80a6847a5cd@calcurse.org>

lfos/calcurse,lfos/calcurse,lfos/calcurse