[notify] openvpn: 2.3.5 -> 2.3.6

This update resolves CVE-2014-8104, a DoS vulnerability exploitable by
authenticated users. Detailed information about this issue can be found at
https://community.openvpn.net/openvpn/wiki/SecurityAnnouncement-97597e732b

(cherry picked from commit 55b2316ba8c2326f433e604538fd2e2529060a4e)