Change ComputeHost table to filter on host field

ComputeHost table was trying to filter on a field that didn't exist
leading to a template rendering error when the filter was applied, so
this patch changes from 'service.type' to 'service.host' as the filtered
field.

Change-Id: I66a47a98f4005689b7be73bec46fa3ea4b9472af
Closes-Bug: 1390089
Merge "Change ComputeHost table to filter on host field"