update vendor

Signed-off-by: Roland.Ma <rolandma@yunify.com>

vendor/github.com/docker/docker/rootless/rootless.go

@@ -0,0 +1,25 @@
+package rootless // import "github.com/docker/docker/rootless"
+
+import (
+	"os"
+	"sync"
+)
+
+const (
+	// RootlessKitDockerProxyBinary is the binary name of rootlesskit-docker-proxy
+	RootlessKitDockerProxyBinary = "rootlesskit-docker-proxy"
+)
+
+var (
+	runningWithRootlessKit     bool
+	runningWithRootlessKitOnce sync.Once
+)
+
+// RunningWithRootlessKit returns true if running under RootlessKit namespaces.
+func RunningWithRootlessKit() bool {
+	runningWithRootlessKitOnce.Do(func() {
+		u := os.Getenv("ROOTLESSKIT_STATE_DIR")
+		runningWithRootlessKit = u != ""
+	})
+	return runningWithRootlessKit
+}