package/nginx-modsecurity: update upstream URLs
'https://github.com/SpiderLabs/ModSecurity-nginx' now redirects to
'https://github.com/owasp-modsecurity/ModSecurity-nginx', so update our
URLs accordingly.
Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
Signed-off-by: Julien Olivain <ju.o@free.fr>