HOTFIX: emails models previous_recipients to allow any status

Don't limit message search to STATUS_SENT messages; we were repeatedly checking the mediawiki api to see if we could email the same non-emailable users.

Bug: T409420

Author: jsnshrmn

TWLight/emails/models.py

@@ -37,9 +37,8 @@ def user_pks_with_subject_list(self, subject, users):
             except ValueError:
                 pass
 
-        # Search for repients of sent messages with the one of the localized email subjects.
+        # Search for repients of existing messages with the one of the localized email subjects.
         previous_recipients = self.filter(
-            status=Message.STATUS_SENT,
             subject__in=subjects,
         ).values_list("to_email", flat=True)