display html error if no scap_content_profile

[shlomizadok]

On policies, if no scap_content_profile is chosen, View guide page will raise an error:

ActionView::MissingTemplate (Missing template scaptimony_policies/parse, application/parse with {:locale=>[:en], :formats=>[:html], :handlers=>[:erb, :builder, :rabl]}. Searched in:
  * "/home/szadok/dev/repos/foreman/app/views"
  * "/home/szadok/dev/repos/foreman-docker/app/views"
  * "/home/szadok/dev/repos/foreman_openscap/app/views"
  * "/home/szadok/dev/repos/scaptimony/app/views"
  * "/home/szadok/.rvm/gems/ruby-2.0.0-p481/gems/apipie-rails-0.2.6/app/views"
):

We can not use warn method.

[isimluk]

Weird. We should be able to generate guide for 'empty' profile. OpenSCAP should be able to generate such guide.

[isimluk]

The patch is good.

But the guide button should work as well.

[isimluk]

Merged as a833d0f.

Also created final fix in c1cef82.