get rid of numerous gcc-4 warnings
diff --git a/extensions/libipt_ttl.c b/extensions/libipt_ttl.c
index 3a25734..db5b002 100644
--- a/extensions/libipt_ttl.c
+++ b/extensions/libipt_ttl.c
@@ -29,7 +29,7 @@
 		struct ipt_entry_match **match)
 {
 	struct ipt_ttl_info *info = (struct ipt_ttl_info *) (*match)->data;
-	int value;
+	unsigned int value;
 
 	check_inverse(optarg, &invert, &optind, 0);