Can assign the targetId by msg.targetId when apply push node.

[huangchinlin]

https://github.com/n0bisuke/node-red-contrib-line-messaging-api/blob/5906ce2769b657db977eec7a47aaa43a359c152f/nodes/push/push.js#L23

the idea is:

const userId = msg.targetId || node.credentials.targetId;