getting Column 'message_id' cannot be null - while we have no null values in table.

Gettign the following error:
```
2018-02-12 15:35:05 ERROR Error 1048: Column 'message_id' cannot be null; query=
replace /* gh-ost `shoutout`.`_messages_gho` */ into
`shoutout`.`_messages_gho`
(`message_id`, `instance_id`, `data`, `date_created`, `date_updated`, `short_code`, `status`, `tags`, `date_sent`, `distribution_status`)
values
(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
```

while:
select count(1) from messages where message_id is null
```
-> ;
+----------+
| count(1) |
+----------+
| 0 |
+----------+
1 row in set (0.00 sec)
```