Allow GW controller to watch namespaces

I don't think that we're explicitly watching namespaces but the
controller library likes to watch.

controllers/gateway/gateway_controller.go

@@ -43,7 +43,7 @@ func (r *GatewayReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Complete(r)
 }
 
-//+kubebuilder:rbac:groups="",resources=namespaces,verbs=get;list
+//+kubebuilder:rbac:groups="",resources=namespaces,verbs=get;list;watch
 //+kubebuilder:rbac:groups="",resources=secrets,verbs=get;list;watch
 //+kubebuilder:rbac:groups=gateway.networking.k8s.io,resources=gateways,verbs=get;list;watch;create;update;patch;delete
 //+kubebuilder:rbac:groups=gateway.networking.k8s.io,resources=gateways/status,verbs=get;update;patch