route-nopull
When used with --client or --pull, accept options pushed by server EXCEPT for routes. When used on the client, this option effectively bars the server from adding routes to the client's routing table, however note that this option still allows the server to set the TCP/IP properties of the client's TUN/TAP interface.
Portanto, adicione route-nopull ao seu arquivo de configuração do OpenVPN. Eu escrevi um post sobre como usar um OpenVPN VPN com cURL / PHP .