[experimental-ims] 5a385b5 Add a necessary #include

[Geoff Simmons]

commit 5a385b581d41002e7bdd19776f262bd35b222c41
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Wed Oct 12 08:44:46 2011 +0000

    Add a necessary #include

diff --git a/lib/libvarnish/vmb.c b/lib/libvarnish/vmb.c
index 3f5c12d..8f130f1 100644
--- a/lib/libvarnish/vmb.c
+++ b/lib/libvarnish/vmb.c
@@ -28,6 +28,7 @@
 
 #include "config.h"
 
+#include <errno.h>
 #include <pthread.h>
 #include <unistd.h>