Small typo fix

Running msfconsole would generate an Ubuntu crash report (?). This seems to be the culprit.

Author: TheNaterz

modules/exploits/linux/smtp/haraka.py

@@ -71,7 +71,7 @@ def send_mail(to, mailserver, cmd, mfrom, port):
     s = smtplib.SMTP(mailserver, port)
     try:
       resp = s.sendmail(mfrom, to, msg.as_string())
-    except smtplib.SMTPDataError, err:
+    except smtplib.SMTPDataError as err:
       if err[0] == 450:
         log("Triggered bug in target server (%s)"%err[1], 'good')
         return(True)