fixing entrypoint

Dockerfile

@@ -20,4 +20,4 @@ RUN mkdir -p /openvpn/pki /openvpn/state /etc/openvpn
 
 STOPSIGNAL SIGTERM
 
-CMD ["openvpn", "--config", "/etc/openvpn/server.conf"]
+CMD ["/usr/local/bin/openvpn-start"]