pam plugin path customization

[catalinpan]

Hi

For x86_64 CentOS systems the openvpn pam plugin path is /usr/lib64/openvpn/plugin/lib/openvpn-auth-pam.so by default.

I have added a new variable which allows to have a custom path because the default one was for another system, I believe. Maybe this will help somebody in the future.

I have kept the old path as default /usr/lib/openvpn/openvpn-auth-pam.so

Thanks

[luxflux]

Thanks, @catalinpan!

I would to handle this in params.pp.
Do you mind adding a variable there and removing the parameter from server.pp? You can follow the pattern of $easyrsa_source in params.pp.

[luxflux]

I had some time and did it myself. Will merge this via #148.