net-mgmt/cacti: add patch for SQL injection in the graphs.php page

PR: 205920
Submitted by: rakuco
Approved by: Daniel Austin <freebsd-ports@dan.me.uk> (maintainer)
Obtained from: http://svn.cacti.net/viewvc?view=rev&revision=7767
Security: CVE-2015-8369
Security: https://vuxml.FreeBSD.org/freebsd/bb961ff3-b3a4-11e5-8255-5453ed2e2b49.html
MFH: 2016Q1