HTML email conversion drops tables and everything trailing it

[zogstrip (Régis Hanol)]

@brechtm

Note that pasting the HTML tables into a post works fine, suggesting that there’s no reason HTML tables couldn’t simply be included as-is into the Markdown post.

The reason was that the code handling HTML to Markdown conversion on the server-side did not support <table>

This will be fixed once this PR is merged

https://github.com/discourse/discourse/pull/9586