Use Openvpn 2.4 only

internal/openvpn/start.go

@@ -13,8 +13,7 @@ import (
 var ErrVersionUnknown = errors.New("OpenVPN version is unknown")
 
 const (
-	binOpenvpn25 = "openvpn2.5"
-	binOpenvpn26 = "openvpn2.6"
+	binOpenvpn24 = "openvpn2.4"
 )
 
 func start(ctx context.Context, starter CmdStarter, version string, flags []string) (
@@ -22,10 +21,8 @@ func start(ctx context.Context, starter CmdStarter, version string, flags []stri
 ) {
 	var bin string
 	switch version {
-	case openvpn.Openvpn25:
-		bin = binOpenvpn25
-	case openvpn.Openvpn26:
-		bin = binOpenvpn26
+	case openvpn.Openvpn24:
+		bin = binOpenvpn24
 	default:
 		return nil, nil, nil, fmt.Errorf("%w: %s", ErrVersionUnknown, version)
 	}