flarum/core — pull request #27 by dz1984 (2014-12-31 04:24:23+00:00)
Title: fix the number_index is null

Pls, PR it.

```
[Illuminate\Database\QueryException]
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'number_index' cannot be null (SQL: upda
te `discussions` set `posts_count` = 38, `start_post_id` = 1404, `last_time` = 2014-05-14 19:49:12, `
last_user_id` = 12, `last_post_id` = 1442, `last_post_number` = , `number_index` = where `id` = 72)

[PDOException]
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'number_index' cannot be null
```