chore(updater): set vpn field for all providers

- Bump servers model versions for all providers except mullvad, ivpn, windscribe
- Do not leave `vpn` JSON field empty for any server

internal/updater/providers/purevpn/hosttoserver.go

@@ -3,6 +3,7 @@ package purevpn
 import (
 	"net"
 
+	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
 )
 
@@ -11,6 +12,7 @@ type hostToServer map[string]models.Server
 func (hts hostToServer) add(host string, tcp, udp bool) {
 	server, ok := hts[host]
 	if !ok {
+		server.VPN = vpn.OpenVPN
 		server.Hostname = host
 	}
 	if tcp {