zebra: add missing includes
diff --git a/zebra/if_netlink.c b/zebra/if_netlink.c
index 701c81b..86bd8ff 100644
--- a/zebra/if_netlink.c
+++ b/zebra/if_netlink.c
@@ -22,6 +22,8 @@
 
 #include <zebra.h>
 
+#include "zebra/zserv.h"
+
 extern int interface_lookup_netlink (void);
 
 /* Interface information read by netlink. */