Guard against None coming out of the draft parser, we need to convert

that into an empty string, fixes ietf-tools#775.
 - Legacy-Id: 3997

Author: OleLaursen

ietf/submit/forms.py

@@ -282,7 +282,7 @@ def save_draft_info(self, draft):
                 TempIdAuthors.objects.create(
                     id_document_tag=document_id,
                     first_name=full_name.strip(),
-                    email_address=email,
+                    email_address=(email or "").strip(),
                     author_order=order,
                     submission=detail)
             else: