ulogd2: Backport upstream patches

IPFIX support was requested.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

net/ulogd/patches/020-fix-musl.patch

@@ -0,0 +1,29 @@
+From 675e762091380590f78ff07a94a25caa459b786b Mon Sep 17 00:00:00 2001
+From: Cameron Norman <camerontnorman@gmail.com>
+Date: Sat, 27 Oct 2018 13:05:45 -0700
+Subject: ulogd: fix build with musl libc
+
+The attached patch fixes building ulogd2 with musl libc. It is being
+used on Void Linux right now.
+
+Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1278
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+---
+ src/ulogd.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/src/ulogd.c b/src/ulogd.c
+index b8bc57c..9cd64e8 100644
+--- a/src/ulogd.c
++++ b/src/ulogd.c
+@@ -65,6 +65,7 @@
+ #include <sys/time.h>
+ #include <sys/stat.h>
+ #include <sched.h>
++#include <limits.h>
+ #include <ulogd/conffile.h>
+ #include <ulogd/ulogd.h>
+ #ifdef DEBUG
+-- 
+cgit v1.2.1
+