chore(storage): remove unneeded VPN default

internal/models/server.go

@@ -2,8 +2,6 @@ package models
 
 import (
 	"net"
-
-	"github.com/qdm12/gluetun/internal/constants/vpn"
 )
 
 type Server struct {
@@ -28,11 +26,3 @@ type Server struct {
 	PortForward bool     `json:"port_forward,omitempty"`
 	IPs         []net.IP `json:"ips,omitempty"`
 }
-
-func (s *Server) setDefaults() {
-	// TODO v4 precise these in servers.json rather than here
-	if s.VPN == "" {
-		// If the VPN protocol isn't specified, assume it is OpenVPN.
-		s.VPN = vpn.OpenVPN
-	}
-}