websubmit : Send_APP_Mail error with record_owners

[chokribr]

I've got this error by using Send_APP_Mail Unhandled TypeError caught when calling [Send_APP_Mail] WebSubmit function: [an integer is required] a Warning is displayed for user A serious function-error has been encountered. Adminstrators have been alerted. Please not that this might be due to wrong characters inserted into the form (e.g. by copy and pasting some text from a PDF file). https://github.com/inveniosoftware/invenio/blob/maint-1.2/modules/websubmit/lib/functions/Send_APP_Mail.py#L244