Oh, that's a little weird, perhaps it's a typo, and should read "proxy_http" instead of "proxy_html"?
As for the local emailer, perhaps you can install @psychobunny's fork?
npm install git+https://github.com/psychobunny/nodebb-plugin-emailer-local
What language is your forum set to?
Yeah, seems to be a language problem (probably a newline got misplaced in a translation somewhere). Depending on what language your forum is using, you can fix it here: https://transifex.com/projects/p/nodebb
It's set to en_US.
Thanks for another quick quality of life fix. It's appreciated!