build: update github.com/vishvananda/netlink to 1.3.0

This includes a breaking change:
acdc658b86
route.Dst is now a zero IPNet instead of nil

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

vendor/github.com/vishvananda/netlink/route.go

@@ -154,8 +154,15 @@ type flagString struct {
 }
 
 // RouteUpdate is sent when a route changes - type is RTM_NEWROUTE or RTM_DELROUTE
+
+// NlFlags is only non-zero for RTM_NEWROUTE, the following flags can be set:
+//   - unix.NLM_F_REPLACE - Replace existing matching config object with this request
+//   - unix.NLM_F_EXCL - Don't replace the config object if it already exists
+//   - unix.NLM_F_CREATE - Create config object if it doesn't already exist
+//   - unix.NLM_F_APPEND - Add to the end of the object list
 type RouteUpdate struct {
-	Type uint16
+	Type    uint16
+	NlFlags uint16
 	Route
 }