security/vuxml: add www/rubygem-rest-client vulnerabilities

PR: 200504
Differential Revision: https://reviews.freebsd.org/D2699
Submitted by: Sevan Janiyan <venture37@geeklan.co.uk>
Approved by: ports-secteam (delphij, eadler)
Security: CVE-2015-1820
Security: CVE-2015-3448