Missing easy-rsa package

[Reinis Ivanovs <dabas@untu.ms>]

The openvpn package in wheezy-backports is not fully usable without the easy-rsa package, which is missing from backports. easy-rsa used to be included in the openvpn package, and not having it in backports seems to be an oversight.

R. <http://untu.ms/>