[PATCH stable]mq: fix traceback when qpush inexistant-patch with no patch applied

[Benoît Allard]

Benoît Allard wrote:
> # HG changeset patch
> # User Benoit Allard <benoit at aeteurope.nl>
> # Date 1254530194 -7200
> # Node ID 577a230a7e354523047be21657777d3bc46ff95d
> # Parent  53a95a74481248a92ea4faf10c302d1e948b7968
> mq: fix traceback for qpush inexistant-patch with no patch applied
> 

ping !