Fix OpenBSD build

The header sys-queue.h must be #included early, otherwise at some point OS
queue macros will be used. On OpenBSD, those don't define TAILQ_FOREACH_SAFE.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

vl.c

@@ -31,6 +31,8 @@
 
 /* Needed early for HOST_BSD etc. */
 #include "config-host.h"
+/* Needed early to override system queue definitions on BSD */
+#include "sys-queue.h"
 
 #ifndef _WIN32
 #include <libgen.h>