Compute plugin list in bash completion for `docker daemon --authz-plugin`

Signed-off-by: Harald Albers <github@albersweb.de>

contrib/completion/bash/docker

@@ -706,6 +706,10 @@ _docker_daemon() {
 	"
 
 	case "$prev" in
+		--authz-plugin)
+			__docker_complete_plugins Authorization
+			return
+			;;
 		--cluster-store)
 			COMPREPLY=( $( compgen -W "consul etcd zk" -S "://" -- "$cur" ) )
 			__docker_nospace