calcurse-caldav: fix basic authentication
calcurse-caldav: fix basic authentication

Read whether basic authentication is used and add the credentials to
httplib2 when making a request.

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

lfos/calcurse,lfos/calcurse,lfos/calcurse