inputs.x509_cert: Fix timeout issue (#8824)

* reproduce timeout issue #8809

* fix timeout issue #8809

* set default timeout to 5s

* closes #8809

Co-authored-by: 彭浩 <penghao@qiyi.com>

plugins/inputs/x509_cert/x509_cert.go

@@ -280,7 +280,7 @@ func init() {
 	inputs.Add("x509_cert", func() telegraf.Input {
 		return &X509Cert{
 			Sources: []string{},
-			Timeout: internal.Duration{Duration: 5},
+			Timeout: internal.Duration{Duration: 5 * time.Second}, // set default timeout to 5s
 		}
 	})
 }