MFH: r427417

Import upstream patch to fix CVE-2016-9296

Null pointer dereference can cause 7z to crash.

PR: 214940
Reported by: Sevan Janiyan <venture37@geeklan.co.uk>
Security: 48e83187-b6e9-11e6-b6cf-5453ed2e2b49
Security: CVE-2016-9296

Approved by: ports-secteam (junovitch)