counter nit: It's not possible to actually do that in the above block, unless we also allow data-l10n-id injection in the template.  Otherwise if language is switched while this `(no recipient)` is rendered, it won't change language.

I told rick to do it this way because of that giant l10n bug I dealt with all of the edge cases,  If you ever catch yourself calling `navigator.mozL10n.get` you're probably doing it wrong.