XUI "Delete Label" is inactive for orphan labels

Install OpenAM 13, configure UMA (provider/agents/etc), and add a resource_set for a user.

• User logs into OpenAM, browses to their resource, and adds a label "Media" for the resource. Now the label is also shown under "My labels".
• User goes to resource page again and removes the label "Media" from it. Still the label shows under "My labels".
• User clicks on the "Media" on the left pane, and sees the attached page. "Delete Label" is inactive!