Only allow one subscription per article

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 6.0.5 GA
• Fix Version/s: --Sprint - SP, 6.1.0 CE RC1
• Component/s: Knowledge Base
• Labels: None
• Branch Version/s:
  6.0.x
• Backported to Branch:
  Committed

Previously, a user could subscribe to an article one time per portlet.

So if a user subscribed to an article, it would show up as unsubscribed in a different kb portlet.

This change makes it so that the article will show up as subscribed across all kb portlets.

Portlet level subscriptions are still separate (Admin / List).