Maint: configuration Openvpn selection structure

- Move network protocol from ServerSelection to OpenVPNSelection child
- Move PIA encryption preset from ServerSelection to OpenVPNSelection child
- Move custom port from ServerSelection to OpenVPNSelection child

internal/configuration/privado.go

@@ -23,17 +23,14 @@ func (settings *Provider) privadoLines() (lines []string) {
 		lines = append(lines, lastIndent+"Hostnames: "+commaJoin(settings.ServerSelection.Hostnames))
 	}
 
+	lines = append(lines, settings.ServerSelection.OpenVPN.lines()...)
+
 	return lines
 }
 
 func (settings *Provider) readPrivado(r reader) (err error) {
 	settings.Name = constants.Privado
 
-	settings.ServerSelection.TCP, err = readProtocol(r.env)
-	if err != nil {
-		return err
-	}
-
 	settings.ServerSelection.TargetIP, err = readTargetIP(r.env)
 	if err != nil {
 		return err