bash completion for `docker node update --label-{add,rm}`

Signed-off-by: Harald Albers <github@albersweb.de>
(cherry picked from commit bc6e3c0b5e)
Signed-off-by: Tibor Vass <tibor@docker.com>

contrib/completion/bash/docker

@@ -2080,11 +2080,14 @@ _docker_node_update() {
 			COMPREPLY=( $( compgen -W "manager worker" -- "$cur" ) )
 			return
 			;;
+		--label-add|--label-rm)
+			return
+			;;
 	esac
 
 	case "$cur" in
 		-*)
-			COMPREPLY=( $( compgen -W "--availability --help --membership --role" -- "$cur" ) )
+			COMPREPLY=( $( compgen -W "--availability --help --label-add --label-rm --membership --role" -- "$cur" ) )
 			;;
 		*)
 			__docker_complete_nodes