Fix ErrorController docstring
Fix ErrorController docstring

The ErrorDocuments middleware has been replaced by the
StatusCodeRedirect middleware in Pylons 0.9.7.

DanielNeugebauer/adhocracy,alkadis/vcv,phihag/adhocracy,phihag/adhocracy,liqd/adhocracy,liqd/adhocracy,alkadis/vcv,liqd/adhocracy,alkadis/vcv,phihag/adhocracy,DanielNeugebauer/adhocracy,alkadis/vcv,alkadis/vcv,phihag/adhocracy,DanielNeugebauer/adhocracy,phihag/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,liqd/adhocracy