Fix for tests following not-guilty path update
Fix for tests following not-guilty path update

Tests were failing because the bad data path was causing errors with
one of the form stages. I've made the stage a bit more robust in the
case of bad data.

[https://makeaplea.leankit.com/Boards/View/126993392/137642372]

ministryofjustice/manchester_traffic_offences_pleas,ministryofjustice/manchester_traffic_offences_pleas,ministryofjustice/manchester_traffic_offences_pleas,ministryofjustice/manchester_traffic_offences_pleas