Change numvcpus to logical_cpus

I found two views that showed data from `numvcpus` instead of `logical_cpus`:

* `vm_common/_config`: shows data collected by `application_controller` using `numvcpus`
* `vm_common/_main`: uses `graphical_group_properties` from `vm_helper/graphical_summary.rb`, which relies on `VM.num_cpu`, which in turn used `Hardware.numvcpus`

Updated both of these underlying culprits to use the corrected `Hardware.logical_cpus` value.

https://bugzilla.redhat.com/show_bug.cgi?id=1006637