Stop ActiveRecord generating nonsense SQL by using .to_a

Without this, the .any? in the view would try to generate a COUNT
query, and with the custom select in the :by_host_and_path_and_status
scope it generates nonsense. We also don't want the overhead of an
unnecessary count.

This fixes the last remaining feature failure.
Remove a duplicate `hits.host_id` in custom select

This wasn't breaking anything.