Merge pull request 'fix: bcc as list in Message build' (#176) from jmplace/ScoDoc-Lille:fix_bcc into master

Reviewed-on: viennet/ScoDoc#176

app/scodoc/sco_bulletins.py

@@ -987,7 +987,7 @@ def mail_bulletin(formsemestre_id, I, pdfdata, filename, recipient_addr):
         bcc = copy_addr.strip()
     else:
         bcc = ""
-    msg = Message(subject, sender=sender, recipients=recipients, bcc=bcc)
+    msg = Message(subject, sender=sender, recipients=recipients, bcc=[bcc])
     msg.body = hea
 
     # Attach pdf