The routes for poll questions were accidentally deleted in commit
5bb831e959 when deleting the `:show` action, and restored in commit
9871503c5e. However, the deleted code was:
```
resources :questions, only: [:show], controller: 'polls/questions' (...)
```
While the restored code was:
```
resources :questions, controller: 'polls/questions' (...)
```
Meaning we forgot to add the `only: []` option when restoring the
routes.
We also forgot to remove the `before_action` code when deleting the
`:show` action, so we're removing it now.
9fbd7eec8f