add registry auth to docker service call

.drone.yml

@@ -33,7 +33,7 @@ steps:
       - name: dockersock
         path: /var/run/docker.sock
     commands:
-      - docker service update --image $${PLUGIN_REPO}:${DRONE_COMMIT_AFTER} $${SERVICE}
+      - docker service update --with-registry-auth --image $${PLUGIN_REPO}:${DRONE_COMMIT_AFTER} $${SERVICE}
 
 volumes:
 - name: dockersock