Potential fix for #1230: failure multi-queue vs resque web
Potential fix for #1230: failure multi-queue vs resque web

Fixes regression caused in [10912ef][], which caused an exception to be
raised in resque web when hitting /resque/failed or /resque/failed/:queue_name

[10912ef]: https://github.com/resque/resque/commit/10912efdcec91de7486e273f203c884db5f523f8

Shopify/resque,resque/resque,xiangzhuyuan/resque,stvp/resque,resque/resque,resque/resque,CloudVLab/resque,CloudVLab/resque,CloudVLab/resque,stvp/resque,Shopify/resque,Shopify/resque,coupa/resque,xiangzhuyuan/resque,coupa/resque,stvp/resque,coupa/resque,xiangzhuyuan/resque