Stop logging email addresses for SES errors

We shouldn't be logging PII so we should not log email addresses. We
remove the email address and just log the normal exception message.

Note, this meant before that you could see the email address and more
easily track down the notification ID in the database. Now instead, you
will need to search in the DB for notifications that have gone into
technical failure at the time of the log message (as we still don't
log the notification ID alongside the failure).

app/clients/email/aws_ses.py

@@ -122,10 +122,7 @@ class AwsSesClient(EmailClient):
 
             # http://docs.aws.amazon.com/ses/latest/DeveloperGuide/api-error-codes.html
             if e.response['Error']['Code'] == 'InvalidParameterValue':
-                raise InvalidEmailError('email: "{}" message: "{}"'.format(
-                    to_addresses[0],
-                    e.response['Error']['Message']
-                ))
+                raise InvalidEmailError(str(e))
             elif (
                 e.response['Error']['Code'] == 'Throttling'
                 and e.response['Error']['Message'] == 'Maximum sending rate exceeded.'