Using OpenVPN over TCP is impossible from LuCI

[Ingmar Runge <ingmar@…>]

Steps to reproduce:
(via LuCi?)
- Add "Simple server configuration for a routed PTP VPN"
- Optionally add a shared secret file
- Try to edit the settings so that protocol reads tcp-server or tcp-client
You would have to activate "Enable client mode" (what does this mean anyway?) for that. However if you save it like that, OpenVPN will error out on start.
- After using "uci delete" to remove "openvpn.server_tun_ptp.client", it works just fine with proto correctly set to "tcp-server" or "tcp-client".

Also, in "basic configuration mode", proto can only be set to "udp" or "tcp", not "tcp-client" or "tcp-server".

Thanks a bunch!