[website] Fix multiLangID for blog post
This name actually applies to this blog post.
The previous one was carried over accidentally from a different article.
Test Plan: ran it locally to check that the post and translated post both still work properly.
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Differential Revision: https://reviews.bitcoinabc.org/D11408