Fix tailing logs stops working sometimes

prometheus-nginx-log-exporter stopped tailing logs on many of my servers
after sometimes and needed a manual restart to start working again.
Switching from inotify (default) to poll might help to fix the issue.

Author: Anh Pham

main.go

@@ -110,6 +110,7 @@ func monitorFile(file string, parser *gonx.Parser, metrics *metrics, extraLabelV
 	t, err := tail.TailFile(file, tail.Config{
 		Follow:   true,
 		ReOpen:   true,
+		Poll:     true,
 		Location: location,
 	})
 	if err != nil {