Remove ‘originally’ from returned letters report

We should remove Originally on the individual report pages.
It sounds like we're saying the letter has been sent more than once
since that date.

The dictionary definition for 'originally' as an adverb says:
> used to describe the situation that existed at the beginning of a
> particular period or activity, especially before something was changed

Examples given include:
> The book was originally published in 1935.

app/templates/views/returned-letters.html

@@ -42,7 +42,7 @@
     {% call field(align='right') %}
       <span class="align-with-message-body">
         <span class="status-hint">
-          Originally sent {{ item.created_at|format_date_normal }}
+          Sent {{ item.created_at|format_date_normal }}
         </span>
       </span>
     {% endcall %}