[ticket/12436] Data passed to sql_multi_insert is expected to be multi-dim.

PHPBB3-12436
Merge pull request #2348 from bantu/ticket/12436

[ticket/12436] Data passed to sql_multi_insert is expected to be multi-d...

* bantu/ticket/12436:
  [ticket/12436] Data passed to sql_multi_insert is expected to be multi-dim.