libipt_REDIRECT: "--to-ports" is not mandatory

The REDIRECT target can be called without the --to-ports option
being specified. From the manual page:
  ...without this, the destination port is never altered.

Signed-off-by: Lutz Jaenicke <ljaenicke@innominate.com>
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/extensions/libipt_REDIRECT.c b/extensions/libipt_REDIRECT.c
index 426a746..e67360a 100644
--- a/extensions/libipt_REDIRECT.c
+++ b/extensions/libipt_REDIRECT.c
@@ -23,8 +23,7 @@
 }
 
 static const struct xt_option_entry REDIRECT_opts[] = {
-	{.name = "to-ports", .id = O_TO_PORTS, .type = XTTYPE_STRING,
-	 .flags = XTOPT_MAND},
+	{.name = "to-ports", .id = O_TO_PORTS, .type = XTTYPE_STRING},
 	{.name = "random", .id = O_RANDOM, .type = XTTYPE_NONE},
 	XTOPT_TABLEEND,
 };