pfSense

openvpn_validate_port() has:
if (empty($value ...

so when passing zero to it complains
(because empty(0) is FALSE):
"The field 'Local port' must contain a valid port, ranging from 0 to 65535"

While I would want it to check for not 0,
the above says zero is okay and the
vpn_openvpn_server.php addInput form for it allows it.

make fix in both places.