add \n in engine labels display in docker node inspect xxx --pretty

Signed-off-by: allencloud <allen.sun@daocloud.io>
(cherry picked from commit ddec4c3ee4e51cb62060f752777bdd32e86607e3)
Signed-off-by: Victor Vieux <vieux@docker.com>

api/client/node/inspect.go

@@ -137,8 +137,7 @@ func printNode(out io.Writer, node swarm.Node) {
 	if len(node.Description.Engine.Labels) != 0 {
 		fmt.Fprintln(out, "Engine Labels:")
 		for k, v := range node.Description.Engine.Labels {
-			fmt.Fprintf(out, " - %s = %s", k, v)
+			fmt.Fprintf(out, " - %s = %s\n", k, v)
 		}
 	}
-
 }