Admin Manage Components table does not hide when there are no components

[Ryan J Ollos <ryan.j.ollos@…>]

Here is a screen capture of the Manage Milestones view with all of the milestones deleted:

Here is a screen capture of the Manage Components view with all of the milestones deleted:

they should behave similarly. The message As long as you don't add any items to the list, this field will remain completely hidden from the user interface. should be displayed and the table header should be hidden when all of the Components are deleted.

The problem is that Component.select returns a generator, and it's not expanded to a list in _render_admin_panel. For all of the other cases of Ticket System fields, select either returns a list or the generator is expanded to a list in _render_admin_panel (e.g. enums).