[{tag}] comes up as undefined in memos

[officiallymarky]

When moving to dsteem version of Post Promoter I notice the blacklist tag memos are showing undefined f or tag.

blacklist_tag config setting (as per example config)

"blacklist_tag": "Bid is invalid - This post contains the [{tag}] tag which is not allowed by this bot.",

Memo sent

Bid is invalid - This post contains the [undefined] tag which is not allowed by this bot.

This used to work, so I suspect it might be something with the dsteem migration