chore(lint): upgrade linter to v2.4.0

- migrate configuration file
- fix existing code issues
- add exclusion rules
- update linter names

internal/firewall/firewall.go

@@ -9,7 +9,7 @@ import (
 	"github.com/qdm12/gluetun/internal/routing"
 )
 
-type Config struct { //nolint:maligned
+type Config struct {
 	runner         CmdRunner
 	logger         Logger
 	iptablesMutex  sync.Mutex