config: enable UDP for openvpn by default

this adds a new helper setDefaults() in the config
package and calls it when the config file  doesn't
exist, this provides a way for us to have  default
values for the config options

setDefaults currently only sets the UDP config  to
'true' since it is expected that UDP is enabled by
default

pkg/config/gui.go

@@ -17,6 +17,8 @@ package config
 
 import (
 	"encoding/json"
+	"errors"
+	"io/fs"
 	"os"
 	"path"
 	"time"
@@ -61,8 +63,10 @@ func ParseConfig() *Config {
 	var conf Config
 
 	f, err := os.Open(configPath)
-	if err != nil {
-		conf.save()
+	if err != nil && errors.Is(err, fs.ErrNotExist) {
+		log.Debug().
+			Msg("Config file doesn't exist. Using default values to create")
+		conf.setDefaults()
 	} else {
 		defer f.Close()
 		dec := json.NewDecoder(f)
@@ -84,6 +88,13 @@ func ParseConfig() *Config {
 	return &conf
 }
 
+func (c *Config) setDefaults() {
+	if err := c.SetUseUDP(true); err != nil {
+		log.Err(err).
+			Msg("Unable to set default for UDP config")
+	}
+}
+
 func (c *Config) SetUserStoppedVPN(vpnStopped bool) error {
 	c.file.UserStoppedVPN = vpnStopped
 	return c.save()