[enhancement] Cannot unassign multiple users from subscription

[grubskim]

1. Create a subscription to any service
2. Go to account/subscriptions
3. Assign some users

[expected] I am able to unassign multiple users at the same time from the subscription. [actual] I have to click on each user I want to unassign, and then confirm the pop-up. This is very inconvenient for managing many users, and could be enhanced by introducing a checkbox, or including all users on the list when you assign them.