Fix mail sending with BCCs

Looks like this was broken in the python 3 migration, but missed since
it only affected cases where a single address was added, and not a list
of addresses. The only user of this was data-purge warnings.

1 files changed, 1 insertions, 1 deletions

diff --git a/postgresqleu/mailqueue/util.py b/postgresqleu/mailqueue/util.py
index a74368a5..7fa063f4 100644
--- a/postgresqleu/mailqueue/util.py
+++ b/postgresqleu/mailqueue/util.py
@@ -60,7 +60,7 @@ def send_simple_mail(sender, receiver, subject, msgtxt, attachments=None, bcc=No
         if type(bcc) is list or type(bcc) is tuple:
             bcc = set(bcc)
         else:
-            bcc = set(bcc, )
+            bcc = set((bcc, ))
 
         for b in bcc:
             QueuedMail(sender=sender, receiver=b, fullmsg=msg.as_string()).save()