fix SMTP output duplicate headers

Signed-off-by: Edgaras <[email protected]>

outputs/smtp.go

@@ -154,8 +154,6 @@ func (c *Client) SendMail(falcopayload types.FalcoPayload) {
 		smtpClient.Auth(auth)
 	}
 
-	body := sp.To + "\n" + sp.Subject + "\n" + sp.From + "\n" + sp.Body
-
 	if c.Config.Debug {
 		log.Printf("[DEBUG] : SMTP payload : \nServer: %v\n%v\n%v\nSubject: %v\n", c.Config.SMTP.HostPort, sp.From, sp.To, sp.Subject)
 		if c.Config.SMTP.AuthMechanism != "" {
@@ -166,7 +164,7 @@ func (c *Client) SendMail(falcopayload types.FalcoPayload) {
 	}
 
 	c.Stats.SMTP.Add("total", 1)
-	err = smtpClient.SendMail(c.Config.SMTP.From, to, strings.NewReader(body))
+	err = smtpClient.SendMail(c.Config.SMTP.From, to, strings.NewReader(sp.Body))
 	if err != nil {
 		c.ReportErr("Send Mail failure", err)
 		return