[Postfix] Remove headers only when mail_name matches

data/conf/postfix/mailcow_anonymize_headers.pcre

@@ -1,10 +1,9 @@
 if /^\s*Received:.*Authenticated sender.*\(Postcow\)/
 /^\s*Received:.*Authenticated sender:(.+)/
   REPLACE Received: from localhost (localhost [127.0.0.1]) (Authenticated sender:$1
-endif
-
 /^\s*User-Agent/        IGNORE
 /^\s*X-Enigmail/        IGNORE
 /^\s*X-Mailer/          IGNORE
 /^\s*X-Originating-IP/  IGNORE
 /^\s*X-Forward/         IGNORE
+endif