Modal for admin unregister does not automatically close

[danielyanghansen]

Steps to reproduce:

• 1: Be admin / author for an event (so you have the rights to admin unregister)
• 2: Have someone be registered to that event
• 3: Go to the registration tab under the event admin page and click unregister (far right)
  
• 4: Click "Ja" under "Bekreft utmelding"
  

Observe: Seemingly nothing happens. Under inspection, everything has resolved and the user is unregistered, but the "Ja" button is greyed out, and the modal stays open.

[SaiNikhil02]

@danielyanghansen can you please assign me this issue