Cancel adding groups(s)/user(s) in Global/Space Permissions is not working

Summary

Cancel adding groups(s) or user(s) in Global or Space Permissions is not working as expected.

Steps to Reproduce

1. Navigate to > General configuration > Global Permissions
2. Click 'Edit Permissions'
3. Add user(s)/group(s)
4. Say you changed your mind and click 'Cancel' instead of saving the added user(s)/group(s)

This also applies to Space Permissions. Please see below screen shots for further visualisation of the issue.

Expected Results

All changes would be ignored and the users and/or groups would not be added.

Actual Results

The user and/or groups is added anyways.

Workaround

Manually remove the added group or user by un-checking the single checked option for the newly added user/group and saving the change.