openvpn user created by openvpn package, so use openvpn user instead.

closes #32.

template/server.conf.tmpl

@@ -248,8 +248,8 @@ comp-lzo
 #
 # You can uncomment this out on
 # non-Windows systems.
-user nobody
-group nobody
+user openvpn
+group openvpn
 
 # The persist options will try to avoid
 # accessing certain resources on restart