[php-maint] Bug#643015: Please add official PHP link to README.Debian.security

[Moritz Muehlenhoff]

Package: php5
Severity: minor

README.Debian.security already explains that safemode and open_basedir bypasses are not
treated as security issues since 2006. There's now also an official link from PHP.net
and it would be nice if you could include the link to the README:
http://www.php.net/security-note.php

Cheers,
        Moritz